I do think that our username policy is handled very badly at times. People are blocked for offensiveness when the offensiveness is rather arguable; people are blocked for impersonation if they happen to pick a name that's close to an existing user; people are blocked for impersonating a well-known person when they're actually using their own real names. Very rarely is it explained properly; very rarely is the person given an opportunity to change their ID or to challenge the decision.
It seems that we constantly assume 'Vandal!' in this case.
-Matt