A good lawyer could convince a jury that requiring real names amounts to a "whites only" or a "men only" rule, which would be illegal.

Good lawyers have surprised me before, but that's so clearly false, as one glance at Facebook will show, that I have to think it would get laughed out of any courtroom.

I do not believe that's true. If it was, somebody would have already dinged Facebook for millions of dollars.

Using this logic, nothing new will ever happen because if something could happen it would have already happened.

Well, let me modify that to say "if something that could have made someone millions of dollars for not doing much could happen it would have already happened", something I fervently believe.