I've just found this fascinating website about Pennhurst:
www.elpeecho.com/pennhurst/pennhurst.htm
It's full of information about the history of the place and has a whole section with documents that forced the closure of Pennhurst. There is even a streaming video option that allows you to see several documentary films about Pennhurst. Has a bulletin board about it too.
I'm going to add it in the "links" section. More about this site as I look it over.