Since this activity is probably scheduled, it would be a good idea to let the FBI know that this has happened. In addition, you could station yourself at some local area prior to the event and capture it on video and send THAT to the FBI and NSA . The problem with these two organizations, though, is that they're reactive not proactive to unusual behavior. Your mileage with them may vary.
For your suggestion, I think one should send the video to the media if you don't get teh FBI to respond (don't send it to the media first though obviously....just if the FBI blows it off)