I've been looking for a video clip of how Saddam Hussein did a purge of the Ba'ath Party in 1979. It was videotaped, I remember seeing it, but I couldn't remember where. 

A big room. Saddam sitting in front smoking a cigar. A thousand people. They start taking them out of the room one by one, to be shot by a firing squad. People figure out what's going on and freak out. Are they next? He makes his closest allies be part of the firing squad. Really chilling. It stayed with me all these years. 

I finally found the video on YouTube. It was in a Frontline episode entitled The Mind of Hussein. It aired in 1991 during the first Gulf War. Here's the video, the relevant part starts around 26:16.