Thoughts on Pseudonyms and Google+
1. If the standard is to use your "real name," how do we define "real name"? Most people assume this is defined by your legal name, so my real name is Stentor Danielson. But I doubt anyone who heard my parents calling me "Stenny" or my students calling me "Dr. Danielson" would protest that they're not using my real name (nor would anyone insist I use my middle name, even though it's on all of my official legal ID just like my first and last names). So what about my brother Zeke? You might say that Zeke is obviously not his real name since his birth certificate has the very different-sounding "Patrick," but in fact "Zeke" does derive ultimately from "Patrick" (via the babytalk mispronunciation "Patzeek").
2. The usual claim is that using one's real name forces you to "stand behind" what you say, because your words are linked to your identity. But in some cases, using your "real name" actually obscures the link to your identity if people commonly know you as someone else. I have a large number of friends from an internet message board, and when I talk to people from that board I refer to other board people by their board screen names. I've declined Facebook friend requests from board members because their FB account uses their real name but I only know them by their board name. (Indeed, I met Richard Chapman, who I linked to above, on said board under a very different name.) Perhaps this could be solved by an internet-wide "real names" policy, so that I would have gotten to know those people by their real names in the first place, but even Google is not in a position to enforce that (yet).
3. Insofar as real names provide "accountability" in the first place (am I going to go to someone's house and punch their offline face for something bad they did online?), the level of accountability provided by a name (real or otherwise) is directly proportional to the rarity of the name and the amount of corroborating details given by the person. As far as I know I'm the only Stentor Danielson on the planet (and by far the Stentor with the largest internet presence), so it's pretty easy to connect my personas in various forums based on my name alone. But I personally know two Matthew Campbells, and this site says there are over a million more in the US alone. Were I to be harassed online by a Matthew Campbell, I would have no way of knowing who it was unless he decided to also, say, include in his profile that he was a member of the Colgate University class of '02. Conversely, if a pseudonymous harasser dropped enough such personal details, I might be able to work out their identity even without the help of a name.
*It's not clear to me why services like this insist on knowing your gender as one of the fundamental pieces of information about you. On Facebook I assumed it was a legacy of the site's original use as a hookup-facilitator for college students.