Actually no. I had been in their IRC for some time during the first couple weeks of the Wikileaks leaks, and it isn't like that. They are a group that, just like any other, like HN, have certain common and shared values and talk, discuss and act by them. In their case, basicly, they are pro free-speech, pro internet and privacy.
They, like we here in HN, organize themselves around those ideas. Sometimes they act together against someone that goes against their values, like they just did to Aaron, and sometimes they act towards other positive goals like they did in Egypt. It is not about being cool, having fun or anything like that. That is just one of the ways they attract kids and other people to join them in their attacks and other actions. There is no central leadership, no hierarchy, but all their actions are done following certain values and ethics that you cannot really grasp unless you are part of it, just like HN.
Although they don't have leaders, at least in their IRC, there are moderators, that, at least during the leaks, when there were over 3 thousand people in a single IRC channel, would lock the channel, summarize arguments, add questions and unlock it, while they were selecting targets. But usually that only happened when there were that many people and too many trolls spamming the chat.
They are people, from all ages that act by their shared values.