With the attack by a chimp on a woman in CT there was plenty of news about how violent chimps can be. This should be no surprise - they are our closest relatives and have pretty much all our vices. As humans would not do well in captivity and a certain number of them would snap and go violent, it should be no surprise that chimps do the same. In Africa, listening to chimps scream in the forest I had a much more visceral reaction than I did to being charged by an elephant or stared down by a lion. There is something deeply familiar, and scary, in their calls - as if we know what they mean on a level we can't put into words, actually.
Keeping chimps in captivity is just an inherently bad idea, though there are some sanctuaries which provide enough natural environment that their lives are not awful. I saw a chimp sanctuary in Kenya though that was dead on depressing as all the chimps knew they were prisoners (all had tried escaping so they kept improving the enclosure) and they were on birth control. Not having babies supposedly contributed to their depression. Although they had a nice environment, they were most definately not happy.
Chimp behavior is fascinating on a number of levels and there have been a few articles in the news, not related to the CT incident, that have caught my attention. Here is a very interesting article on a chimp that stockpiles weapons for pre-planned attacks on human visitors at the zoo. Here's recent video and a study on chimps that use clubs to break open bee hives and obtain honey. In the Congo, four baby chimps were recently taken from people who had killed their families and planned to sell them for the pet trade. One died, but the other three made it to a sanctuary. You can read about that and see great photos here, here, here, here, and here.