Ripped off by A-Bodies member!!!!

Don't you have a way to prevent that by identifying his I/P address? I remember a few yrs. ago a lunatic signed up and started posting lewd pics (real nasty ones) in the general forum. They banned him and he'd sign right back up. After about the 4th or 5th time the mod taking care of it (John, can't think of his screen name, not a mod anymore) closed him down again and said something about putting a bug (possibility cookie?) on the offenders PC so he could never sign up again. It seemed to work cause he went away and this guy was a real lunatic, not the kind you'd expect to just go away on his own.
You would think there would be a way to block his ip address somehow......but then the OTHER excuse will apply, he has multiple IP addys....it is not like banning some one takes an hour, just log onto the mod page click a few buttons, give a reason why and it is done....