What part of Facebook's TOS did the removal fall under?

It depends where you do it, I think. If you call somebody a name in real life or over the phone, the worst they can do it hit you. If you post derogatory comments online, where anybody in the world can see them, then a hefty punishment is not only expected, but also—in my opinion—appropriate. If one's comments are warranted (calling Bin Laden "an evil terrorist", for example) or stem from differing viewpoints ("Gordon Brown is a bad prime minister"; "Charles Darwin was wrong about evolution"), then it is not right to punish them for it, but in the case of applauding the actions of this man—who is nothing more than a terrorist, whatever he and his supporters choose to call him—Facebook were certainly right to remove the comments.

Most of the groups did not applaud the actions, they applauded the thoughts. I have no comment on those without reading them carefuly and thinking it over, but it is important not to dismiss his points merely because of the murderous way in which he chose to make them. I often agree with the words of dictators; it does not mean I support them.