Not all DMs take it to extreme weirdness. You just fell in with wackos.
To the OP, your choice. Do a bunch of stuff back at him, and get labeled as just as bad as he is, or ignore him and let him stew in his own nastieness. Unless you have some illegil lizards, the officials aren't going to do diddley squat. He hasn't threatened you, just called you a few names. Calm down, and ignore his junk.
If there WAS anything you could do, I'd be all for it. But from my own recent experiances, there isn't. I'm 90% sure I know who you're talking about, and he's probably got every duck in a row as far as his own operation. YahooGroups couldn't care less about how the groups are run, and will tell you to drop out from his group and to block his emails.
