We think it's a user by the name of Aaron92. He's barely 15 and was banned from the site for being underage. He also attempted to contact another banned user in an admitted attempt to troll the site together.
Every time we ban an account, he creates a new one, which is why he keeps coming back.
He's trolling because I assume he has nothing else to do. Despite the fact that he claimed he is "done with the Backrooms," he keeps coming back (obviously). We live rent free in his head, and it's incredibly pathetic that he hasn't moved on.
As far as I know, there's not much we can do at the moment, at least not without revealing some security features staff is trying to implement. For the moment, we ask you immediately report any users with usernames related to Team Fortress 2 that have an account age less than a month. Also, let staff know of vandalism you see, and we'll do our best to revert the changes.