It's well known that Albert Einstein was a brilliant physicist. It's fairly well known that he was also an outspoken pacifist and civil rights activist. One might suspect that these latter facts would have rankled a few people, and one would be right.
The FBI conducted ongoing surveillance of Einstein until his death in 1955. In 1983, Dr. Richard Alan Schwartz wrote about Einstein and the FBI for The Nation. Since then the censorship of Einstein's file has been reduced, and Fred Jerome (hardly a neutral author, which may rankle a few people as well) has written a new book on the topic, to be published this month.
The New York Times wrote about all this today (you can use "songdog.net" as username and password)