You have Anon completely wrong SSJ. Anon are in general the people who post on a group of imageboards that allow (and almost solely use) anonymous posting. Thus they are a collection of people that use the net, generally some of the more extreme people (given the stuff that turns up in your average /b/). They are therefore not an organization or even a group, merely a random bunch of internet users who occasionally have similar ideas and visit similar boards. There is no 'being a part' of anonymous as the entire idea of anonymous is that every single person is nobody. Just visit 4chan.org and go to /b/ for a while to understand what I mean.
Anyway some Anon enjoy going on 'raids' against things such as Habbo Hotel and anything else that for some reason or another pisses them off and Scientology just happened to do that by threatening legal action against youtube to get the video removed, Anon likes to think that the web belongs to Anon and thus the attack on scientology began.
The attack on MS, those ISPs and stuff would all have begun with a pissed of Anon setting up a raid and all the other anon going along for the lulz.
I think this picture sums up Anon pretty well.
