FYI, Facebook is now effectively a part of the US government. A judge has just ruled that State prosecutors will be allowed to search the Facebook records of two people in connection with the #J20 protests, despite those two people not being charged with any crimes. They're also prohibited from appealing the ruling, meaning that your 4th amendment rights do not apply anymore.
@knightly it sounds like they're going on a fishing expedition to try to find any information which could be used to get a conviction. It's also a reminder that if you are organizing an event which the government might not like then FB might not be the best place to do it.