My impression was that something about naim in particular triggered their wrath, since as you say, Gaim and Trillian rarely provoked ire. But their support was

My impression was that something about naim in particular triggered their wrath, since as you say, Gaim and Trillian rarely provoked ire. But their support was unhelpful, and it happened a couple times to more people than just one user at once, so _something_ about it was clearly rustling their jimmies. They did eventually seem to back off though, as the sibling commenter said, because after a certain point I stopped randomly getting banned ever again from then until the end of AIM as a service.