Let me begin by saying that I was a target of impostors today. Now, I have a different outlook on the impostor situation.
While I realize that it can be a bit annoying if the impostor(s) spams, it is all in good fun. No one is trying to take over another persons account, steal passwords, or anything like that. They are merely having fun with the targeted subject. If having fun is against the rules here, then that is ridiculous in my opinion.
I agree with those that have suggested a limit be put on how many posts can be submitted in a certain amount of time, however.
But I can't see how one can be banned for having a similar name. It's no different than those that complained recently about so many people having "their color". There are so many colors that one may choose and no one owns a certain color.
The same goes with names. If the name is different, then I don't see where they are breaking the rules. If somehow they figure out how to make identical names, then I agree that something must be done to deter this. But banning is not the way to go unless it is suspected that one is trying to get the real person banned or is trying to steal an account, etc.