This week Google+ officially changed their name policy to not necessarily require real names. Specifically in cases like mine, I am allowed to be Tobold on Google+, as long as I can provide "Proof of an established identity online with a meaningful following". So you, my readers, now officially gained the title of being "meaningful following". :)
Blizzard, after having failed with their RealID idea, has also come to the same conclusion that a permanently used pseudonym has basically the same benefits with regards to avoiding the negative effects of anonymity than a real name has. So they introduced the Battle Tag as alternative for Diablo 3 and World of Warcraft. It is "a unified, player-chosen nickname that will identify each player in all Blizzard games, on the official websites and in the community forums". Needless to say I already reserved my Battle Tag.
The odd man out is still Facebook, who appear not be willing to change their requirement of using only the name printed in your passport. Unless you are famous enough to get your complaint in the New York Times, like Salman Rushdie, who got his Facebook account first deactivated, then renamed to "Ahmed Rushdie", before Facebook caved in to massive protest.
As the Economist recently noticed, social media worked in favor of the dissidents in the Arab Spring only because the Egyptian secret police were "digital dullards". In other countries, like China, social media with a real name policy are more likely to work in the advantage of the state to identify dissidents than to the advantage of the dissidents to organize protests. But those concerns are mostly extreme cases, which journalists like to discuss. The far more common reasons for wanting not to use your real name have been listed by Danah Boyd, and span everything from teachers that want privacy from their students, to gays in small towns that only want to "come out" online, and not in real life. A lot of good reasons to avoid leaving a very public display of all your interests on the internet are work related, as some sort of separation of work life and private life is often a good idea. If I was developing online games, I sure wouldn't want all those internet crazies to know where I live. And most people with "serious" jobs and "frivolous" hobbies don't want the link made between the two.
As Facebook's $100 billion valuation rests solely on the goodwill of its users and customers, I consider their real name policy and repeated breaches of privacy a real risk. It is easy enough to imagine a "Facebook scare" after some criminal or organization used Facebook to target / identify victims. Many people tend to neglect to value their privacy sufficiently up to the moment when they are reminded of the possible negative consequences, at which point they tend to overshoot into the other extreme. It is better for people to protect their privacy early on, and for companies to give them the technical means to do so. Fixed pseudonyms are a very good option here, and should be more widely accepted.