@darius I disagree,
This is a moral decision, not one based on what's practical or technically convenient, or the most useful.
You can keep your username and leave your profile completely empty and locked so that nobody steals your identity, nobody links to anything you said, and you don't dignify anything with that.
It's okay for people to use whatever advantage they can gain from their oppressors.
But to each their own, everybody is free to make their own decisions.
@vruz you will notice that I said "it's important for me". Anyone else can do as they please. I am speaking from my experience and in fact was very careful to word my statement in a non prescriptive manner.