Susan Arendt said:
So, I have a question - if Anonymous is this amorphous blob with no organization...who decides what to put in the open letter?
I'm sure your question have been answered already a few times, but if not, I'll try to explain it.
Anonymous is like a collective group of ideals and morals merged into one. To give an idea, lets use an example of say, a mob. This mob has hundreds of random people mashed up together, milling about doing absolutely nothing. Suddenly, someone wants to move, and they shout "Hey, let's move over to the next street!" Suddenly, the mob begins to do this due to not having anything else to do to occupy itself, or it feels like it should morally move there, for whatever reason. Along the way, lets say there's some obstructions, such as trash cans. No one has to shout "move the trash cans," because when they reach it, the closest members already begin to move it without thought. They do this mainly because of "the group is more important than the individual" mentality.
But along the way, there are some that shout "lets kick some trash cans along the way to the street!" Suddenly some begin to kick trash cans just because they can, or because it amuses them, while the rest continue on to the street.
It's a unified mass that has no leader, that has no goals, but is a collective. One thought is passed around, and should anyone believe it's a worthwhile thought, then they'll commit to it and soon it gives them a reason and objective to complete. So for the one that posted the open letter is one of the people that has to "move the trash can" along the way, as it is a necessity for the overall goal they're working on.
(Sorry for the long, boring post)