Ya, you were being cute, but Lulzsec was Sabu and his group. Anonymous is whatever a random group of people decided to that day and call themselves Anonymous. Tomorrow it will be a different group of people with a different and potentially conflicting cause.

It's still a proper noun relating to a specific group of people. It's like a team name - just because the roster of the Steelers change over the years doesn't mean that 'Steelers' is not a name.

Edit: 'Anonymous' is a team name, I mean, not 'God' :)

God is an idea that makes people feel better about themselves and to put themselves on a moral high ground over others.

What makes the Steelers the Steelers is not the roster, it is the paid position of the Coach and the owner of a legal entity and a defined goal and purpose. Anonymous is none of that.

Anonymous is anyone. It could be a bunch of people protesting Wall Street today. Tomorrow a group could call themselves Anonymous and protest Westboro Baptist. The day after a group calling itself Anonymous might break into Sony's systems. They might be all the same people, some of the same people or none of the same people. Each group might be made of people that agree with the others or vehemently disagree. It is not a specific group of people, it is not eve a coherent group of people.