You really can. In my experience, people respect your choices. They may pity you (if they're the type that generally pity anyone different than themselves), they may find it funny, they may actually lean toward feeling the same way, but just not feel as strongly. People still respect your wishes.
Sometimes I feel that people have reached a point where a vast majority couldn't understand why a person would want to write a novel under a pen name, or donate anonymously, or work quietly. They can understand wanting to make up a name, but just to have a cooler name, not as a misdirection.
Sure, you can make a request, and most people will respect it. But you can't make it as a demand. If I want to tweet "I was out partying with pessimizer last night" there is no reasonable way (short of libel laws) to stop me.
This is the part I don't understand. ok, we shut down Facebook tomorrow. All those people talking about you aren't going to move to LiveJournal or whatever? Are we going to shut down flickr and wordpress, too?
Good heavens, imagine the clusterfuck it'd be if everybody ran their own server, as advocated by at least one HN post per week. You'd never be able to shut them all down!
