I had huge problems with an AOL member and they kept getting a new IP address each time the logged in because of the way AOL dishes out random IPs. You can ban them va their various IPs but it affects all other users with the same IP. A better option would be the hacks I coded that fixed my issues and it didn't impact my other users. Once the user logs in, these codes no longer have an impact (well other then No-Register as that one forces the problem IP to e-mail and beg to be added to the user database):
See:
IP NoRegister:
https://vborg.vbsupport.ru/showthread.php?t=129280
IP NoPost:
https://vborg.vbsupport.ru/showthread.php?t=129277
IP NoView:
https://vborg.vbsupport.ru/showthread.php?t=127288
Hope this helps some as I have been there with a real PITA user and it can be tough to get rid of a determined problem but this solved the issue for me!