Wooooh! Yeah! Hoots , hollers and dance music played on a full-volume boombox, assail the conference room where I am quizzing a data scientist at Facebook. It takes 20 seconds for the noise to die down enough for us to continue talking.

This is what Facebook’s offices are like, embracing at least the idea of “creative destruction”, violence to the establishment. Facebook will soon float its shares on the stock market, making several billionaires and many millionaires out of its staff and backers. But the sprawling new Menlo Park office complex is designed—perhaps a bit too designed—to look as if the kids just took over in a revolution. Walls are extensively, if rather meticulously, graffiti’d; the graffiti artist, who was paid in shares, will be among the new millionaires. Chalkboards line many of the remaining surfaces, so Facebook’s wandering young employees can doodle almost anywhere. There are blocks of conference rooms with whimsical names: one here based on Star Wars characters mixed with drinks (Darth Jager, The Empire Strikes Bacardi), one over there echoing Ben & Jerry’s ice-cream (Americone Dream, Half Baked). Signs abound reading “Move Fast and Break Things”.

But these kids are not really breaking things. They are relentlessly building things, one after the other after the other, and adding them to the vastly ambitious mega-thing called Facebook. With its initial public offering (IPO) approaching, the company is in a “quiet period” during which it must avoid making new public predictions, but it is expected that Facebook’s 850m users will grow to a clean billion by July.

So for all the capricious decor and talk of breaking things, Facebook is very well aware that the eyes of the world are on it as an incumbent giant, not an insurgent. Besides “Move Fast and Break Things” there are signs telling employees to “Stay Focused and Keep Shipping”. Visitors are greeted warmly, but also presented with the standard Silicon Valley non-disclosure agreement before they can proceed past security. A billion people connected as never before in history. But Facebook also engenders anxiety on levels from the personal to the political, worries about a world in which private lives are always on display. What is 24-hour social networking doing to our self-expression, our self-image, our sense of decorum? Have we finally landed in the “global village” coined by Marshall McLuhan in the 1960s? What if you don’t like it there? Is there anywhere else to live?

And what is Facebook, anyway? The most obvious point of historical comparison is the social networks that preceded it. First there was Friendster, the flirt-and-forget site of the first half of the 2000s. Then everyone dumped Friendster for MySpace, and MySpace was bought by News Corp for $580m. Its value soared to $12 billion, and the received wisdom was that MySpace would take over the world. Then it didn’t, and News Corp sold it for $35m, because someone else had finally got social networking right. Started by Mark Zuckerberg in 2004, Facebook went from a Harvard dorm room to the rest of teenage America’s bedrooms to hundreds of millions of people all around the world—even parents and grandparents. Along the way, Facebook has fuelled revolutions in the Middle East, and inspired an Oscar-winning movie. Other social networks can only try to build out from the few niches it hasn’t already filled. Facebook is the undisputed champion of the world.

But the real comparison is not with other social networks. To give real credit to its achievement today and its ambitions for the future, it can only be said that Facebook’s true competitor is the rest of the entire internet.

The internet allows three things, broadly speaking: access to content (video, music, things to read), self-expression (blogs, Twitter) and communication (e-mail, chat, Skype). Facebook competes with it on all these fronts. By one estimate, one minute in every seven spent online, anywhere in the world, is spent on Facebook. To express themselves, users have Status Updates. For content, they can find photos, videos, music, news stories, recipes, book reviews and much more. And for communication, of course, there are your friends and Friends. More and more, the point of Facebook is to do almost anything you would do anyway, but with your friends, online. Facebook is an internet within the internet, so dominant that both it and other technology companies are realising that it is far easier to join forces than to fight.

Take Spotify. This Sweden-based company is on the way to being the first music-sharing service getting right what Napster and others once tried and failed: to get people to pay small amounts to listen to music online, or to put up with ads. What do you do about Spotify, if you’re Facebook? Time spent on Spotify could drag users away. So Facebook’s approach is make Spotify users Facebook users. If your cousin Bob is on Spotify, you and his 234 other Friends can see that he is listening to “Somebody That I Used to Know”, and listen along if they want to. Far from competing with Facebook, Spotify enhances it—and the other way round.

Twitter, with its micro-blogging, would seem to be a direct Facebook competitor. It is smaller, with 383m users in January 2012, but growing faster, and its use by celebrities and journalists, plus its role in the Arab uprisings, has made it the social network to watch. So how does Facebook feel about Twitter? “We shouldn’t be competing with almost any of these people.” So says Andrew (“Boz”) Bosworth, Facebook’s 30-year-old director of engineering. Barrel-chested and talking a mile a minute, Bosworth is visibly enthusiastic one second, cheerfully irritated with what he sees as misconceptions the next: his catchphrase seems to be “I don’t want to tell you what to write, but if I were writing your article…”

Bosworth is not only happy about working with the likes of Twitter, he is exuberant. He cites Facebook’s partnership with Skype: “You wanna specialise in video calling? Awesome!” But you and your company would be well advised to work with a certain platform that begins with “Face” and ends with “book”. “If you’re a start-up today, you can leverage the world’s largest social network. For free. Why would you want to do the really hard thing, which is recreate a social network, when what you can do is focus on the technology you want to build, and use the one that already exists?”

The prospect of access to Facebook’s billion has brought in ever more partners. Pinterest, an online pinboard growing faster than Facebook or Twitter did in their infancy, is a partner. So is GoodReads, where people can talk about the books they’ve read and want to read. Online gaming, facilitated by Facebook, helped power a four-year-old games company, Zynga, to a $1 billion ipo in July 2011. Facebook’s offer to potential competitors is “grow with us, not at our expense”.

This highlights a key feature of Facebook: it is the anti-Apple. Apple’s products are designed down to their molecules so that you never forget who made them. The colours, fonts and distinctive shapes give Apple an ever-present personality. This reflects the top-down, “we know best” culture cultivated for decades by the brilliant authoritarian Steve Jobs.

Facebook could not be more different. “‘Authority’ is just not a word here,” Bosworth says with a laugh. “It’s not a thing we use.” Of course if Mark Zuckerberg, the billionaire 27-year-old founder, has an idea, others will listen. But so will they listen to the junior-most developer who wants to make something new. One forum for this is the Hackathon. The boombox that interrupted my interview was, I later heard, carried by Roddy Lindsay, a Facebook developer, marching around the halls in a cape for the traditional Hackathon commencement. At the Hackathon, developers join together under one rule: you cannot work on what you normally work on. If that sounds like Google, with its 20% rule, this is a lot more raucous. They fire up new ideas, toss out old ones, collaborate, blow off steam and make things. Most won’t work. Some will: the Spotify app that allows users to listen along with their friends came from a Hackathon. The culture of “why not this too?” keeps the giant growing and constantly changing.

In contrast with its spectacular power, Facebook shows an unintimidating face to the world. The bland blue design is more like a default blog template than the biggest website ever. The plain lower-case logo looks almost sorry to bother you. Tiffani Jones Brown, who oversees the writing of much of the text on the site, says that its personality must be nothing more than “simple, human, clear and consistent”. The music app is called…Music. The photos app is called Photos. The message service is called Messages. Everything on the site is to be written so that an 11-year-old can read it—even though Facebook likes its users to be at least 13.

All this is by design. Bosworth says “You didn’t come to Facebook because we’re so awesome. You came to Facebook because your friends are awesome. They’re doing interesting things and you want to know about it. Time that you’re spending conscious of Facebook as a thing probably means we made a mistake.” The obvious contrast, again, is with the even bigger company up the road. “Your Apple product might actually still be fun without your friends. Facebook is just the most boring product on the internet without your friends.”

Whether this is naivety or modesty, the world is certainly not bored by Facebook. It is not merely an empty place where friends come to hang out, or an open platform other companies can plug their technologies into. Facebook’s reach can be seen in raw numbers: the 850m users, the 8 billion chat messages a day, the billion photos uploaded every four days. But it is not just a technological marvel, a youth movement or a business story. After just eight years of existence, Facebook is the biggest social phenomenon since the telephone.

The Facebook community looks more and more like the world itself. Technology has traditionally been seen as a male preserve. Programming, gaming, message boards, the early days of blogging, all call to mind a male nerd in a black T-shirt. But Facebook was at near gender parity from the start. Now, female users write 60% of comments and share 70% of the pictures. Among American Facebookers, 18% of females update their status at least once a day, according to the Pew Internet & American Life Project, while just 11% of males do so. Women and girls are simply keener social networkers than men and boys. This makes Facebook’s decision to keep its whizz-bang technology out of users’ faces not just a clever bit of design, but a canny strategic decision.

Which they increasingly do, not just across the gender divide but around the world. Around 80% of Facebook users are outside the United States and Canada, and this while being banned in China. (For a point of comparison, about 63% of iPhones were sold outside America in the last quarter of 2011.) Russia and Vietnam are among the rare countries where another social network is bigger. Despite its American DNA, Facebook was so prominent in the Arab spring that when Wael Ghonim, the Egyptian activist whose imprisonment became a cause célèbre, was asked where the next revolution would be, he replied: “Ask Facebook.” Tiffani Jones Brown says that one of her most complicated jobs is keeping Facebook’s “clear, human, simple” tone across the many different languages and cultures Facebook is reaching.

Finally, Facebook is growing older—and not just one year older each year, either. As the habit spreads upwards from kids to their parents, the median age has steadily climbed, although Facebook prefers not to say by how much. This is a challenge for its designers, who want to present a simple experience to new users, while also appealing to those who expect their favourite sites to be buzzy and innovative. As growth continues to “the second billion” Bosworth breezily mentions, Facebook will be used on slower devices with slower connections, making it harder than ever for it to work equally well for everyone.

As Facebook reaches further into every corner of our lives, it also engenders confusion, annoyance and concern. The litany of complaints is familiar. “People are going to be so busy writing about their lives that they forget to live them,” as a friend complains to me, is perhaps the most typical. This “Facebook isn’t real life” trope spans many sub-complaints. The word “friend” is being devalued by having hundreds upon hundreds of “Friends”. Users’ pages are not a genuine portrait, but a careful selection of photos and updates that amount to an illusion. People should be enjoying their vacation, not taking hundreds of pictures of it and putting them on Facebook. People should spend more time curling up with real books, not waste time bragging about what they read via GoodReads. The birthday messages that pour in because Facebook told your “Friends” it was your birthday are no substitute for real friends who actually remember. And so on.

Facebook is now competing with older and older technologies. The voice call over the telephone is a competitor, says Gabe Trionfi, a user-experience researcher for Facebook. But he sees no problem with this. He leans over his laptop to perform a search of public posts for “Feeding 2am”. This produces a list of posts of women nursing their children in the middle of the night, Facebooking on their phones with their free hand. This is something no one would have done on the phone before. Mothers, with babies to their breasts, are reaching out to their sisters. Could anything be more human?

Another piece of evidence that Facebook is no longer just an internet company is another old technology it is challenging: the car. Ford, which participated in a Hackathon with Facebook, is trying to integrate it into its cars via Ford Sync, its hands-free entertainment and communication system. And well might the car try to catch up with the social network. American teenagers are no longer getting drivers’ licences as early as they once did. Getting a licence immediately after your 16th birthday used to be nearly automatic for those in car-owning households; in 1988, 45% of 16-year-olds got a licence. By 2008, that number had fallen to just 30%. The rising cost of petrol and insurance will have played some role in this, but surely Facebook has too: it makes young people feel less cut off, just as it brings together friends or relatives on different continents. Cue, again, the complaints that people are too busy social networking to live “real life”.

Bosworth is merrily impatient with these complaints. “The things people complain about in real life, it’s like they rediscovered them on Facebook. It’s like gossip never existed before, as if your history never followed you around before. I’m not saying there’s not some differences—but these aren’t Facebook problems, they’re just fundamentally human problems.” The philosophy is simple, he says: “Humans talk. Maybe we should let them talk online.”

So “talking” is neither good nor bad. But Facebook means that what people are saying will never again be far away. Long ago, everyone was in regular physical contact with most of the people they would ever know. Everyone knew everyone’s business, but “everyone” was not many people. Then urbanisation, cramming together people from far-flung places, allowed us to vanish into the crowd. Now Facebook is mashing today’s vast crowds into the small town of old, making a world that is both exhilarating and unsatisfying, with more people than ever to keep up with, and more people than ever keeping tabs on you. One study of many on the phenomenon of “Facebook anxiety” produced a simple but striking finding: people’s moods were depressed after reading their Facebook news feed, compared with a control group. One of the researchers attributed this to the fact that most status updates are positive. Reading an endless stream of mostly upbeat news from friends can cast your life in a bad light.

But that is far from fair to the full spectrum of life on Facebook. Life’s hardships are lived socially too. There are groups for people with MS and HIV. A group brings together those with Asperger’s Syndrome and their families. Characteristically, they share both problems and the neurological differences of which many “Aspies” are dead proud. Obsessions are compared—baseball, cooking, dinosaurs, telephone boxes—and commonalities unearthed: many Aspies, it turns out, love Lego, and creations are gleefully shared.

When a call for help goes out, Facebook becomes the world’s biggest megaphone. I discovered this after hearing news of a rangy blond jock I’d played American football with in high school. Will was diagnosed with cancer in 2009, the year his first child was born; he was 34. Since then, the “Support Will Jones” public group on Facebook has racked up 1,500 members. Will has posted triumph, setback, triumph, setback and triumph. Around 900 people have offered him their prayers. When there has been good news, people have plied him with congratulations, which look heart-rendingly premature now. Two years later, Will is still alive, but tumours continue to reappear and require treatment. In “real” life, friends might have moved on or lost heart – it is crushingly hard to support someone with cancer over three years offline. But on Facebook 44 people cheered Will’s latest piece of good news. If Facebook makes it too easy to express the vapid or insipid, it also allows us to go on benefiting from the far-flung relationships they might otherwise have let go cold.

Facebook’s staff eagerly point to a June 2011 study of 2,200 American users of social-networking sites. Far from confirming that Facebook atomised and isolated its users, the Pew Internet & American Life Project found that they had about 9% more strong offline social ties than non-users. (The effect was similar for other non-Facebook networks like Twitter and LinkedIn, and it held up when demographic variables were controlled for.) Facebook users were more likely to agree that “most people can be trusted”. And they have more diverse social networks—counter to the claim that social networking facilitates social bubbles.

They are more politically engaged: Pew found that frequent Facebook users were two and a half times as likely as others to attend a political rally, and 57% more likely to try to influence someone to vote. These numbers were not controlled for demographics, so they do not show that Facebook causes political engagement. But a study by Facebook’s own data team did find that Facebook gets people to vote. In America’s 2010 congressional elections, a box showed most Facebook users the names of some friends who had voted. (Some users were shown no box, or a different box that simply exhorted them to vote, to provide control groups.) Cameron Marlow, one of Facebook’s data scientists, says that the study found that as many as a million people, out of a total turnout of 91m, may have voted who otherwise would not have.

As David Kirkpatrick, author of “The Facebook Effect” (2010), puts it, “Ordinary people, if they are pissed off, will use Facebook to communicate it to the world. It is the easiest tool they have ever had.” To overwhelm an opponent’s Facebook page, posting angry comments faster than they can be deleted, is a new kind of activist victory. Kirkpatrick ticks off a list of stories in his inbox, delivered that day by a Google Alert for the words “Facebook protest”, running through a dozen—from the life-and-death to the mundane. He notes that Twitter played a special role in catalysing protests that had already begun in the Arab spring. But “the alert to follow the Twitter feeds starts on Facebook.” Could people even revolt against Facebook on Facebook? As Kirkpatrick notes (and Bosworth also told me), the news feed, Bosworth’s own baby, was wildly unpopular when it was introduced in 2006. How did Facebook know people were angry? Angry comments spread like brushfire, through the news feed. “If it’s increasing usage,” Kirkpatrick says, “they disregard the protest.”

So is there no sense in which Facebook has changed our lives for the worse? Kids drink and misbehave and then put the inevitable photos on Facebook, embarrassing themselves and even hurting career prospects. Fights between family members are seen by hundreds of outsiders. Lovers canoodle for the entire online public. Changing views of privacy are probably the domain in which critics have the most defensible point. A generation is growing up saturated with the idea that nothing is too personal to put online.

Relationships can now begin and end on Facebook. As I was writing this article, an old friend found his girlfriend sex-chatting with an ex (via Gchat, not Facebook). Whether he would stay with her or not was quickly resolved, when his status was publicly changed to Single, as every one of his “Friends” instantly found out in their news feeds. (The kids, and Facebook’s staff, call this “making it ‘Facebook official’.”) My friend asked me to Unfriend the ex. With mixed feelings, I did this thing, this verb that did not exist ten years ago.

A week later, a second close friend also broke up with his on-and-off girlfriend of five years. In their last stint together he had never become Friends with her, for fear of the endless drama. (“Why is she writing on your wall?...”, and so on.) But I was Friends with her. Should I Unfriend her, I asked, trying to get familiar with the rules of “Facebook official”. No, he said. He didn’t want to hurt her needlessly.

Will a backlash against “too much information” ever hit Facebook? Around 75 years ago, the world’s biggest threat was totalitarian governments, which would throw citizens into prison not just for public opposition but for private “thought crimes”. The right to a private life was a core part of freedom. Today, Facebook is a weapon against oppression—ask the former presidents of Egypt and Tunisia. But it also allows a world in which people have joined to become a modern, hip, social kind of voluntary Big Brother themselves, putting more data about themselves in each other’s (and Facebook’s) hands than Hitler or Stalin could ever have dreamed of. The comparison is absurd, of course; Facebook is a happy money-making company in California, reliant on our consent, not an evil government in Moscow or Berlin. But privacy nudniks cannot be wholly laughed off when they say people are losing valuable, time-worn habits of discretion.

Facebook has already added the ability to sort Friends into Close Friends and Acquaintances, so that not everyone has to share everything with colleagues or clients. But a potential rival has built its entire service around this concern. Google+, launched officially last September, had reached 90m total registrations by February (although Google will not say how many use the site monthly, the direct comparison to Facebook’s 850m or so monthly users).

Vic Gundotra, a senior vice-president at Google, says that when he was researching the prospects for Google+, people repeatedly raised mocking air-quotes when describing their Facebook “Friends”. Google+ is built around “Circles”, customisable by users, so that they can easily share only among close friends, family, co-workers, people who watch “True Blood” on television, or some other common characteristic. Facebook allows segmentation like this in various ways too, but Circles are core to Google+, built around the insight that not everything should be shared with everybody. Two-thirds of content shared on Google+ is shared with limited circles rather than being made public.

Google has good reason for taking on the social-networking giant, as Facebook seeks to integrate nearly every activity users might fancy. Google too has built an entire ecosystem of products: search, phones, e-mail, chat, photo-sharing, music, books, and now Google+. Apple, too, has Facebook in its sights; the new version of its operating system, Mountain Lion, closely integrates Twitter, but has no such easy Facebook functionality. Twitter is cute and unthreatening; Facebook’s ever-expanding universe menaces Apple’s, with its iPhone, iPad, iCloud, iTunes, iMovie, iBooks and more. As Google’s Gundotra says, there are only so many hours in the day. Time spent with eyeballs on your company’s products is money. Apple, Google and Facebook are increasingly competing to offer a complete world to their users.

Even if Facebook should fall—as Friendster and MySpace rose and fell—its reverberations will be lasting. Google made the internet navigable. Apple made it portable, through intuitive, brilliant devices. Now Facebook has made it social, raising a generation that will never again expect things to be otherwise.

Facebook has not replaced social life. It has tightened the social fabric, in a way that fits many people, and which many just as clearly chafe against. The social ills ascribed to it are, by and large, not new. Once people suffered from hysteria and melancholy; in the modern age, they have anxiety and depression. Once they suffered gossiping and bullying; now it’s “Facebook official” drama and cyber-bullying. Once they could envy the greener grass on their neighbour’s side; now it’s “Facebook anxiety” about his (or, more likely, her) online photos. Once they wondered if their social lives were fulfilling enough; now they suffer FOMO—fear of missing out—and get to see all the pictures from the party they weren’t invited to. New labels for old problems. But these problems are larger-looming and becoming ever-present for the millions who can’t get enough of their social networks. And unplugging from Facebook to get a month’s or a year’s peace is an increasingly cranky-looking decision. For the majority of Facebookers who can’t leave the site alone, its ubiquity means that the good and the bad, the joys and the miseries of the social world will never again leave them alone either. “Like” it or not.

Postscript After this piece was written and edited, my high-school classmate Will Jones, whose "Support Will Jones" Facebook page had gathered over 1,500 well-wishing members, died of cancer, aged 36. Hundreds of fresh posts appeared on the group page and on Will's personal Wall, many addressed directly to him. My condolences to his family and friends. ~ RLG