Fascinating list from Mandatory.com regarding the above.  I knew of a few of them, didn’t about others, but found the list interesting nonetheless:

http://www.mandatory.com/2013/03/25/10-people-you-didnt-know-were-spies/

The inclusion of Walt Disney is interesting.  I knew about his right wing/anti-union philosophy but didn’t realize it extended to being an informant against supposed communists.  Different times!