You'd have to try really hard if you wanted to IP track people who pissed you off, and even if the imms could, I doubt they'd care enough.

Furthermore, I expect anyone who has pissed off the imms enough to get on their ####list could spend 5 minutes searching google and mask their IP address through any number of proxies.

Finally, a lot of toxic players have really distinctive playstyles, and half the MUD has them picked out before they delete. I know I've been able to pick out the patterns of half a dozen players without even needing to look at IPs. Some people would have good RP and a decent playstyle and forget certain capitalizations. Others would whine in a very specific way every time they died, or throw OOC hissy fits over things that anyone else would just shrug off. I can only imagine the imms see several times as much information as an average player, and have even less trouble picking up on distinctive habits.

So if you're an obnoxious little bitch and the imms hate you and they've picked you out LONG before you deleted, you have only yourself to blame - not only could you have masked your own IP with very little effort, but you probably gave yourself away just by being a douchebag.

The players who would lose the most from imms tracking IPs are the toxic whiners - I fail to see exactly why the imms would be interested in non-griefy non-whiny non-cheating players, aside from them being, y'know, interesting.