There was a time when whistleblowers like Edward Snowden were as famous for their mysterious identities as they were for the secrets they revealed.
Deep Throat, the infamous whistleblower who revealed the Watergate scandal that brought down President Nixon was thought to be anyone from Henry Kissinger, to Diane Sawyer, to George Bush Snr.
But in the internet age, no-one stays anonymous for long. Snowden's identity, and his location in a Hong Kong hotel, was revealed just 24 hours after his last leak went public in the Washington Post.
Edward Snowden has fled to Hong Kong
"In the high-stakes chess game of intelligence activism the only move open to Edward Snowden was to go public. It would have taken the NSA less than a week to determine his identity, after which his liberty would have been taken away," security expert Simon Davies told HuffPost UK.
Davies, the associate director of enterprise at the London School of Econimics and founder of Privacy International, said it remained to be seen whether revealing his identity would backfire, as he is held up to scrutiny.
"From a campaigning perspective there are pros and cons to having a single identity connected with an issue of this magnitude.
"There are some issues where personalising a battle can be powerful. It is yet to be seen whether this is one of those. An anonymous figure allows people to create their own hero profile. One advantage to an identified whistleblower is that Snowden moves the controversy from the theoretical to the physical. In complex issues that can be very important."
Snowden, 29, an American IT administrator for the defence contractor Booz Allen Hamilton, revealed his identity at his own request, the Guardian said.
And it appears to have just the effect on public opinion the whistleblower probably hoped it would have.
Within hours of revealing his identity, a hashtag had begun circulating, #IStandWithEdwardSnowden, and apetition demanding a pardon for “national hero” Snowden has been registered with the White House.
With a goal of 100,000 signatures by 9 July 2013, at time of press the petition had reached 42,000.
It calls for “a full, free, and absolute pardon for any crimes he has committed or may have committed related to blowing the whistle on secret NSA surveillance programs.”
But some political commentators are already accusing Snowden of fame-seeking. In a op-ed for the New Yorker which went viral on Twitter on Monday night, Jeffery Toobin called Snowden a "grandiose narcissist who deserves to be in prison.
"Any government employee or contractor is warned repeatedly that the unauthorized disclosure of classified information is a crime. But Snowden, apparently, was answering to a higher calling."
Whatever the motivations for revealing his identity, and personal details about his home life in Hawaii, his family and his girlfriend, it has left the US government with much limited options to pursue him, Davies told HuffPost UK.
"It's likely that the next move will be to call on Snowden to voluntarily present himself for a dialogue with US authorities. The last thing they want right now is an Assange style story.
"Best to appear to act reasonably and let Snowden be portrayed as the guy who won't cooperate. They will probably let the heat die down and move in with an extradition request in three months.
"There are many other issues the NSA needs to deal with right now, including that this affair could motivate other whistleblowers. They will be very concerned about a possible contagion effect."
Snowden told the Guardian's Glenn Greenwald he had no regrets about his actions, and said the unconstrained collection of data was destroying civil liberties.
He said: "I can't allow the US government to destroy privacy, internet freedom and basic liberties.
"My sole motive is to inform the public as to that which is done in their name and that which is done against them."
He chose Hong Kong as a refuge because of the former colony's “spirited commitment to free speech and the right of political dissent.” But the country does have an extradition treaty with the US.
Staff at a luxury hotel in Hong Kong told Reuters that Snowden had checked out at noon on Monday. Ewen MacAskill, a Guardian journalist, said later in the day that Snowden was still in Hong Kong.
"He didn't have a plan. He thought out in great detail leaking the documents and then deciding rather than being anonymous, he'd go public. So he thought that out in great detail. But his plans after that have always been vague," MacAskill said.