I once (maybe 2 years ago?) made a 2nd account to troll a guy for 5 minutes like that.
I barely altered the username and for the avatar I opened it in MSpaint and drew a goatee.
I posted once as a joke then closed it.
A moderator warned me not to do that again 
Someone just recently closed his year+ long account at another site. Chess rating never improved despite 1000+ games. Banned from playing a certain variant for engine use. Seems he's "bored" once again and up to the old tricks.
Support can definitely help there - they can change your account name, switch your details to your new account, things like that. Threatening someone else is also a very clear breach of the Terms of Service and is usually an instant mute at the very least.
well, yesterday was annoying. especially @BoboTheFlyingCat66 and @BoboTheFlyingCat68.
What happened to @BoboTheFlyingCat67.....?
Did the vets get to him before chess.com ?
well, yesterday was annoying. especially @BoboTheFlyingCat66 and @BoboTheFlyingCat68.