TONY JONES, PRESENTER: We're now in what's called the post-Snowden era. It's two years to the day since Edward Snowden leaked a huge tranche of documents from the US electronic spy agency, the NSA, and exposed a vast global surveillance net beyond most of our imaginings.

Just to remind you, Snowden revealed that the US and its allies, including Australia, were working together to try to capture the world's internet communications - all of them. I

In one leaked presentation, the NSA put it this way: they want to, "sniff it all, know it all, collect it all, process it all and exploit it all ...".

EDWARD SNOWDEN, FORMER NSA CONTRACTOR (Last night): It's the famous Cardinal Richelieu quote: "Give me six lines written by the hand of the most honest man and I'll find something in them with which to hang him." The problem is they don't have six lines anymore, they have six billion lines on all of us.

TONY JONES: Even so, Snowden's revelations are so numerous and technical, a lot of people just shrug their shoulders and say, "So what?"

But the British comedian John Oliver found one cheeky issue which does resonate on the street.

VOX POP (April 5, Last Week Tonight): If my husband sent me a picture of his penis and the Government could access it, I would want that program to be shut down.

VOX POP II: They should never, ever, the US Government, have a picture of my dick.

EDWARD SNOWDEN: Well, the good news is there's no program named the Dick Pic Program. The bad news is they are still collecting everybody's information, including your dick pics.

TONY JONES: Overnight, the US surveillance state was rolled back just a fraction. Congress passed a bill which officially ends the NSA's bulk collection of American phone metadata.

RAND PAUL, REPUBLICAN SENATOR: So it's a big blow for freedom this week that we're telling the President, "No more." The Government is no longer going to collect all of our records all of the time.

TONY JONES: But when it comes to the internet, the daily bulk collection of data is likely to continue, one way or the other, which may explain why there's rapidly growing interest on how to protect online communication through encryption.

In a moment we'll speak with journalist Glenn Greenwald, who broke the Snowden story, and to Australia's shadow Attorney-General Mark Dreyfus. First, Margot O'Neill finds out why some Australians want to go crypto.

MARGOT O'NEILL, REPORTER: Encryption was once the domain of expert mathematicians, spies and hackers. Not anymore.

Welcome to the world of crypto parties, where everyone from politicians to businesspeople and activists gather to learn how to encode internet communications to ensure privacy.

SCOTT LUDLUM, GREENS SENATOR: This event, I should say, sold out in about 40 minutes, so that is a bit of a measure, I suppose, of the degree of interest.

MARGOT O'NEILL: Crypto parties are a global phenomenon.

They're driven in part by concerns about rampant online crime, but also by Edward Snowden's spectacular revelations of pervasive global surveillance by the US electronic spy agency, the NSA, and its allies.

BRUCE SCHNEIER, DIGITAL SECURITY EXPERT: There was a survey, a worldwide survey about the Snowden documents and what people were doing in response to them. And I ran the numbers and about 700 million people around the world have changed their habits due to the NSA and Edward Snowden. Now maybe what they did wasn't effective, but it's extraordinary how many people are taking steps to preserve their privacy in this world of extensive government surveillance.

MARGOT O'NEILL: Tom Sulston from technology company ThoughtWorks helps run crypto parties around Australia. Last week he trained journalists in the federal press gallery.

We asked him to explain some basic secrecy techniques, such as encrypting emails.

TOM SULSTON, THOUGHTWORKS: I can type in a secret message. And you can see that it turns the message into what is effectively gobbledygook, what we call ciphertext. But we can type in our passphrase to decrypt that message, so that returns it back to the original message.

MARGOT O'NEILL: But it's mobile apps like Wickr, Confide, WhatsApp and many others that are taking encryption to the masses.

Federal Communications Minister Malcolm Turnbull admits using Wickr, an app that encrypts then destroys messages once they're read, and he says others should also think about encryption.

MALCOLM TURNBULL, COMMUNICATIONS MINISTER (March 19): You, the journalist, have an obligation to protect your sources and using encrypted messaging applications and taking care that you don't leave a electronic trail is very important.

MARGOT O'NEILL: It seems encryption is going viral.

KATIE MILLER, LAW INSTITUTE OF VICTORIA: We held an event at which we educated lawyers about the use of virtual private networks and also certain applications on smartphones and it was an absolute sell-out event. We had so much demand. We people saying afterwards that they weren't able to get in and would the event be run again?

MARGOT O'NEILL: It even unites left-wing and right-wing activists

KELSEY COOKE, GETUP!: We're seeing a shift towards making sure that we can encrypt the information that's passed on to us to make sure that we can protect the identities of people who might be communicating about wrongdoings.

CHRIS BERG, INSTITUTE OF PUBLIC AFFAIRS: I think some of the revelations that we've learnt over the last couple of years have been widely understood to be far in excess of the level of invasion of privacy that we expect in a liberal democracy and that's been the most shocking part of it. I think people expect governments to respect their privacy more than they do.

MARGOT O'NEILL: But just when you thought encryption might mean it's safe out there after all, think again. The Snowden revelations also sparked what's being called the crypto wars, and like all conflicts, it involves an arms race.

The Snowden documents reveal that the NSA and its UK counterpart, the GCHQ, have been cracking open encryption around the globe, even boasting that, "Vast amounts of encrypted internet data ... are now exploitable," and that the NSA leads an, "aggressive, multi-pronged effort to break widely-used internet encryption technologies," as well as efforts to weaken international encryption standards.

So tech companies like Apple, Google and Facebook are hitting back, upgrading to ever-more-sophisticated encryption.

For instance, Apple's new iPhone operating system gives each user their own encryption key. The company can no longer break its customers' codes and over data to the Government and US officials aren't happy.

LAURA HARRIS, THE NOW HOST: Recently top Government officials echoing concerns about not being able to gain access to phones in order to solve crimes.

REPORTER: The FBI has contacted Google and Apple over how they're marketing the encryption changes.

DIANE CHO, REPORTER: Means more privacy protections for Apple customers, but for law enforcement officials, it could mean more headaches.

MARGOT O'NEILL: The US and UK governments are pressing for a technology regime in which they can always see when users try to go dark on the internet.

BARACK OBAMA, US PRESIDENT: Social media and the internet is the primary way in which these terrorist organisations are communicating.

DAVID CAMERON, UK PRIME MINISTER: We should try to avoid the safe havens that could otherwise be created for terrorists to talk to each other.

MARGOT O'NEILL: But Apple's chief, Tim Cook, remains hardline.

TIM COOK, CEO, APPLE: People have entrusted us with their most personal and precious information. We owe them nothing less than the best protections that we can possibly provide.

MARGOT O'NEILL: With Sydney biker gangs now reportedly using encryption to order murders and other crimes, Australian law enforcement is also deeply concerned about whether it can break encryption.

NEIL FERGUS, CEO, INTELLIGENT RISKS: In this country, there is absolutely unequivocal evidence of those people that are involved in recruiting or trying to groom and recruit young Sunni Muslims using encrypted devices and encrypted VPIs to do that and they have changed the means and the mode by which they've been using it.

MARGOT O'NEILL: Meanwhile, the crypto parties roll on, spurred by last week's declaration in a United Nations report that encryption is a human right in the digital age, and far from trying to hack it, the report says, governments should strengthen their citizens' ability to remain anonymous online.