Facebook doesn't go out and actively eliminate users they think have pseudonyms. Google+ does.
Facebook just reserves the right to ask you for your government ID, if there's a dispute or you need to reclaim an account. But in practice pseudonyms are tolerated unless you make a nuisance of yourself.
Facebook just reserves the right to ask you for your government ID, if there's a dispute or you need to reclaim an account. But in practice pseudonyms are tolerated unless you make a nuisance of yourself.