What was the last documentary you watched?
If you liked this and haven't seen The Cove yet, it is a must-see.The last one I think was Blackfish, the story of Killer Whales in captivity at Seaworld and other aquariums. Apparently the attendance has dropped significantly as a direct result of the documentary.
If you liked this and haven't seen The Cove yet, it is a must-see.