Zhao Jing recently suffered an unexpected parting of the ways with his alter ego. The Chinese political journalist and blogger is better known as Michael Anti, the name under which he writes. The pseudonymous character was deemed "real" enough for Harvard university to award Mr Zhao a fellowship in that name.
But Facebook decided earlier this year that Michael Anti did not exist. Under rules that require the social network's members to use their real names, he had to go. No matter that the fictitious Mr Anti had more than 1,000 Facebook "friends", his account was suspended without notice.
"I have used the name for more than a decade â€“ my reputation is based on that," complains Mr Zhao. "No one in the virtual world knows my real name."
Facebook's increasing insistence on the use of real names, along with a similar policy enforced by the rival Google+ service launched this year, could end up having profound consequences for life online, changing a world that has long been free and easy into a more controlled place.
That is not just because an increasing part of online life is taking place inside the networks. Both Google and Facebook see their social networks as "stores" of online identity that can be used to unlock other services on the web. They hope to make themselves hubs for a wider range of activity, reaping profits as other companies tap into their stocks of personal data.
As more social interaction moves online, and users are drawn to where their friends and family already congregate, it will become harder to remain outside the worlds created by the social networks â€“ or to eschew the unitary, real-world identities they require of their users.
One of the hallmarks of the web has been the freedom it confers on users to act anonymously â€“ or, as in Mr Zhao's case, pseudonymously. That has promised a degree of liberation from the social and political constraints of the real world. Given the role social networks have played in organising political protests, human rights activists have been among the loudest objectors to the enforcement of "real names" policies.
The licence to remain unknown has also mirrored important assumptions about the real world. "We have an analogue society that gives us a lot of space to do things without revealing who we are," says Viktor Mayer-SchÃ¶nberger, professor of internet governance and regulation at Oxford university. From the freedom to appear in a public place unrecognised, to being able to buy things for cash in a way that leaves no trace of the individual purchaser, anonymity is something most people in free societies take for granted.
They also enjoy the freedom to alter the face they show the world depending on where they are and what they are doing, says Mr Mayer-SchÃ¶nberger. That could be threatened by the insistence on a single, coherent and "real" online identity. Such an approach is "too simplified," according to Mr Zhao. "People use various identities," he says.
Another casualty of this policy was Salman Rushdie, the author whose Facebook account was briefly deactivated last week after the company ruled that he should have used his first name, Ahmed. But Mr Rushdie's complaints on Twitter attracted enough attention to persuade Facebook to back down.
Google has a similar policy to Facebook and has acted more aggressively to enforce it, ejecting users whose names did not appear to be "real" from its Google+ network. Those included the American sex writer Violet Blue â€“ though the search company was forced to backtrack after conceding that this was in fact a legal name.
When it also rejected an account user known only as Skud, it added to the spreading backlash. Skud turned out to be the widely used "handle" of a former Google employee called Kirrily Robert, who went on to document the impact of the purge on early users of Google+. Many operated under well-established online pseudonyms and were exactly the type of "early adopter" that new services rely on to generate attention. Google has since tried to soften enforcement but has not materially changed its standpoint.
Google and Facebook both stand solidly behind the principle of bringing real identities to the web. Forcing users to appear under their real names improves security and brings more civility to online discourse, they claim. "We fundamentally believe this leads to greater accountability and a safer and more trusted environment for people who use the service," a Facebook official says.
The ability of Facebook to get most of its members to use their real names represents a breakthrough in online behaviour, says Fred Stutzman, a fellow at Pittsburgh's Carnegie Mellon University and a researcher in online activity. The sense of security it projected encouraged users to reveal their identity widely on the web for the first time. But the company's subsequent shifts in privacy settings â€“ making more of its users' personal information public by default â€“ eroded some of that trust, he adds.
Online communities where people are forced to disclose their true identities have also been welcomed by child safety advocates. Yet the rules also rob children of the ability to remain anonymous, something that could make them more vulnerable to bullying, according to critics.
Conducting all your online activities under a single, "real" identity also promises to make the web more useful in important ways, according to the internet companies. Other sites that connect to Facebook, for instance, are able to use the Facebook identity information to personalise the services they present to users. Eric Schmidt, Google's chairman, appeared to have something similar in mind recently when he said that requiring Google+ users to appear under their real-world identities would enable the company to make its own future services more valuable.
Ambitions such as these have led some to question whether the internet companies are putting their own interests ahead of those of their users. Mr Zhao, for one, says he has little doubt about what lies behind the shift to real names: "I think Facebook and Google want to expand their power into the real world."
As the primary stores of online identity, according to this view, they are out to make themselves the hubs around which activity on the web revolves. Linking real identities from profiles to other information that social networks have about users â€“ such as browsing habits or histories of online purchases â€“ could make them formidable marketing machines.
Recent missteps over privacy by both companies may have raised doubts about their motives. Yet the concerns are not new. A decade ago, Microsoft was the one in the line of fire over an ambitious online identity service called Passport, which anticipated parts of what Facebook has since achieved. The service was intended to act as a single repository of identity that users could take with them around the web, authenticating themselves as they went.
Coming at the height of Microsoft's dominance of the information technology world, it was widely seen as an attempt by the software company to insert itself into all transactions online. In the event, people were not "clamouring for a single Microsoft identity service to be aware of all their internet activities", wrote Kim Cameron, an expert on online identity at Microsoft.
Nor, he added, did other internet sites much like the idea of Microsoft becoming involved in their dealings with their own customers. The software company was eventually castigated by US regulators for collecting information about people's internet browsing habits without their knowledge, and admitted it had overreached.
Facebook has clearly learnt from that debacle. With four times as many users as Passport, it has progressively won over other internet sites that are looking to lure visitors with "social" features that rely on tapping into Facebook's database. Users of Spotify and other online music services, for instance, can see what songs their friends are listening to when they log into the services through their Facebook accounts.
Yet the full implications of being associated online with a single, real-world identity are only dimly understood. Mr Stutzman at Carnegie Mellon, along with two other researchers, recently conducted an experiment that demonstrated the uses to which the information could be put. Armed with anonymous pictures of volunteers, the researchers were able to use facial recognition software to identify one-third of the subjects by linking to their public Facebook profiles. They were also able to uncover a wealth of other information such as the subjects' personal interests and, in some cases, parts of their social security numbers.
Aside from the obvious privacy concerns, demonstrations of this nature point to how the insistence on the use of a "real" identity can rob people of freedoms. "It's built on the false analogy that in the real world you only have one identity," says Mr Mayer-SchÃ¶nberger. In reality, he adds, people in the physical world choose to identify themselves in different ways depending on the context â€“ or simply to remain anonymous.
Facebook has made much of its attempt to "map" real-world social interactions on to online behaviour, but this is one area in which it has fallen short. Indeed, here as elsewhere, it sometimes appears to be challenging traditional ideas of privacy and social behaviour rather than simply emulating them. In The Facebook Effect, author David Kirkpatrick quotes Mark Zuckerberg, its co-founder, on why a single online persona should suffice: "Having two identities for yourself is an example of a lack of integrity."
Whatever the reaction to such comments, Facebook's emergence as a de facto standard for online identity raises plenty of questions. Among the most important: whose job will it ultimately be to verify, maintain and control identity information?
As with other sources of important personal information "the credit scores that US credit bureaus maintain for individual consumers, for instance "there is a danger in relying on a single source of identity data, says Vivek Kundra, a former White House chief information officer. A reliable system requires multiple sources to "triangulate what the truth is", he says.
Whether Facebook or any other internet service is in a position to assume such a central role in online activity is still an open question. The tensions caused by "real name" policies suggest that such companies will find it hard to govern every aspect of online life, and that users will turn to alternative services if they sense their privacy is being compromised.
Mr Zhao, for one, has moved on to Twitter â€“ a service that has made a virtue of allowing its users to operate under pseudonyms â€“ to give new life to his Michael Anti persona. With Facebook's rejection, he says, "I felt like I'd been disconnected". But in Twitter he adds that he has found a service that better suits his needs, and he no longer feels cut off: "Facebook is not the internet."
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