Troll Management: Handling Conspiracy Theorists on a Forum (2009)
raincoastermedia.com
raincoastermedia.com
The implementation of which was creating a 'Purgatory' forum where there was absolutely no censorship and if people crossed the line too often they were restricted to that forum (though anybody else who wanted to actually engage them could also post). It pissed them off, but in almost all cases, instead of registering new accounts and flooding the main forum with posts (as often happens with banned trolls), they just spout off for a couple days at most, and then either calm down or fuck off of their own accord.
I find it just as effective as an IP ban and less likely to affect others.
The WELL might have had an anti-banning ideology, but it also had an ideology that everything a person writes must be written "under eir real name", with the dual consequences of much-higher reputational consequences for bad behavior and everyone's realizing that if the administration ever did decide to ban a user, getting around the ban would be a lot more involved than just using Tor, a TCP relay or getting a new IP or email address.
(Unimportant details: The real names of most participants were probably verified when they paid the monthly fee by check or credit card. By "under eir real name" I mean that every post had a Unix user name attached, and there was a policy that every user's ~/.plan file had to contain eir real name.)