Not censorship per se, depending on how you understand censorship, but three letter agencies in the US often have an "advisorial" function in the production of many movies, particularly war movies. Most of the time you will even find them credited.

Their influence usually shows itself in how america/troops/wars are portrayed, such as negative language being replaced by neutral statements - but sometimes there are bigger changes.

http://www.independent.co.uk/voices/hollywood-cia-washington...