Makes you a giant stinky chicken shit.
Seriously. Huge example of this yesterday. Someone changed their NN just to have a go at someone else. Not only that, but they even made their new NN well snidey to match what they thought of the other poster.
Seriously folks. If you want to argue with someone, or bitch at someone or kvetch about someone, at least have the strength of character to do it in your usual NN.
Changing to a snide name to make snide comments makes you look like Queen Cunt of Cuntington, and makes you lose any of the moral high ground that you may be sitting on in your head.
Its childish, its cowardly and it makes you a giant stinky chicken shit.