It's really just another form of manipulating jj2 these hackers are doing lately and it's quite easy to reproduce. I've seen it happen many times in many servers. In some cases the hacker is not even required to be in the server to talk through your name. When it happens just ignore it and tell the people in the server that someone is hacking your chat. Since this is happening quite often nowadays, peple should understand and be reasonable about it.

~Ol