One day last month about 40 noisy protesters gathered outside the home of the Facebook co-founder Mark Zuckerberg in Palo Alto in California's Silicon Valley. They chanted slogans and held up signs as a small, select group of people arrived in sleek sports cars and were ushered inside the relatively modest residence where the billionaire lives with his wife, Priscilla Chan.

It must have been an unusual experience for Zuckerberg, 28, whose position as head of Facebook is more likely to inspire admiration or curiosity from Americans rather than outraged, placard-waving demonstrators shepherded by local police. But this was no ordinary party. It was his first political fundraiser and his choice of candidate raised eyebrows: the Republican governor of New Jersey, Chris Christie.

Under the gaze of protesters, Republican bigwigs such as Condoleezza Rice arrived to pay homage to – and write cheques for – a governor who has taken stances against gay marriage and the issue of raising taxes on the rich, while at the same time embarking on a union-bashing crusade against teachers in his home state.

But the fundraiser was just one of Zuckerberg's moves into politics. This week the Wall Street Journal reported that he was helping to organise a political advocacy group with other top tech leaders. The unnamed organisation would lobby for reform on issues such as immigration, education and scientific research. The newspaper said that it had raised millions of dollars from donors and had an initial target of $50m.

It is a remarkable development but also inevitable. The tech sector that has sprung up from Silicon Valley and other development hotspots across the US has grown into a multibillion-dollar industry whose top companies – such as Google, Facebook and Twitter – have reshaped how most of us live. As it grew in power and influence, it was bound to enter politics, seeking to change policy and win allies across the political spectrum. To Big Oil, Big Pharma, Big Tobacco and Big Banking, you can now add Big Tech. This raises an important question that is rarely asked: as they increasingly seek to shape American politics, what do the titans of tech want?

Kate Losse thinks that question needs a lot of attention. She should know. She was an early employee at Facebook and rose to being Zuckerberg's speechwriter before leaving to write a book about her experiences, The Boy Kings.

It seems that her book was aptly titled, and recent tech advances into the political world, especially the creation of a well-funded political organisation, are probably only the tip of an iceberg. "The fact that this sort of development is happening suggests there is a political project," Losse said. "That is why it is important to ask questions now. Otherwise we might wake up one day and there is a whole system in place that we did not see coming."

As with any major industry, the people involved in Silicon Valley have political views across the spectrum. But in general they are often a blend of social liberalism and free-market economics. It is a world where people are happy with ethnic diversity and sexual freedoms but distrustful of big government and see the "heroic entrepreneur" as an aspirational ideal. It is a political culture that owes a debt to libertarian novelist and philosopher Ayn Rand, who preached that free-market self-interest was the future and the hand of government was little more than a dead weight on creativity.

To many, those sort of beliefs in the very young, very rich and very powerful minds of Silicon Valley could be a dangerous mix. "The youth is there in Silicon Valley culture and the hubris is pretty high too," said Paul Argenti, a communications professor at the Tuck school of business at Dartmouth, New Hampshire.

Some of the agenda can be seen in the issues and politicians that the industry is seeking to back. For example, it is lobbying aggressively to relax immigration laws on the highly educated. That may or may not be good policy, but as a values system it is no vision of egalitarianism of the sort that America was founded upon. It is replacing the huddled masses yearning to be free with not-so-huddled elites bearing PhDs. That may suit the belief system of tech start-up people, but less so union members, the working class or the millions of Americans struggling with high levels of joblessness. "By attaching himself personally to this sort of issue, Mark Zuckerberg is young, arrogant and naive," Argenti said.

The way that the sector is seeking to wield power politically is anything but naive, and actually old school. Tech bosses are pouring millions of dollars into lobbying firms. They are bucking a trend too. Overall, the amount spent on lobbying by all industries has been falling since 2010 and the number of lobbyists in Washington has been declining since 2007. But not in tech; the sector has grown each year since 2009, signing up more big-name firms and pouring in millions more dollars.

Google is the leading company in the sector and has hired former top politicians – such as the former congressman Richard Gephardt and the former congresswoman Susan Molinari – to fight for its interests. Facebook has lobbied on bills about privacy, seeking to protect its business model of exploiting its users' content and data as a way of marketing to advertisers. It has a former congressman on board as well, with John Shadegg.

Senior tech executives have also wooed politicians at the highest level. Zuckerberg and the Google chief executive Eric Schmidt were two of the dozen tech titans who attended a private dinner with Barack Obama in 2011. In one of his state of the union addresses, Obama called out Facebook and Google by name as the natural heirs to the great industrial innovators of America's past. Facebook's chief operating officer Sheryl Sandberg has just published a book aimed at creating a social movement of women in the office. She too spans the private and public sectors, having worked as a senior official at the US treasury: no doubt her contacts book still contains a host of powerful government officials on speed-dial.

Observers say this is a tried and tested model for any large industry. "They are singing from the same playbook as everybody else and this is big money. You will find that rarely does a big corporation spend big money except to protect its own commercial concerns," said Sheila Krumholz, the executive director of the Centre for Responsive Politics, a watchdog group that monitors the power of money in US politics.

Yet tech has tried to paint itself as different. Google's informal mantra of "Don't be evil" has helped to craft its image as a socially responsive firm that would be fun to work for. Facebook markets itself simply as a way of connecting people.

Advocates of Twitter say that the company helped to bring down dictatorships in the Arab spring. The legions of Apple fans believe that their favourite firm's sleek products make the world a better – and much more aesthetically pleasing – place to live and work.

But critics see that happy, hippyish public image as a potential trojan horse for a mega-powerful industry hellbent on pursuing its self-interest. Facebook, Google, Twitter and a million other internet-based products might be fun and convenient and make our lives better, but their commercial interests are as real as any oil company, defence manufacturer or bank.

"They have had a honeymoon period," said Krumholz. "But it might be starting to wear off. They have the same corporate interests as anyone else." Except maybe they are on an even bigger scale. Other big industries' products do not shape people's lives in the way search engines and social media sites do. Google and Facebook and Twitter have not created new products that stand alone like a car or a new house; they have created things that invade every other aspect of the economy and our culture. That is a different level of power.

Losse has seen this close-up. Working with Zuckerberg, she says he would frequently see Facebook as becoming a rival to nation states in the future. "Companies over countries," he would say in meetings.

When Zuckerberg talks of a "Facebook nation", it is not idle marketing-speak; he means it. "They are trading the very nature of social interaction. They are very much in people's lives. Don't mistake these companies for fun. They don't see it that way," Losse said.