From USA Today:

An estimated 200 demonstrators, some in wheelchairs, picketed Monday night’s premiere of Tropic Thunder to protest the movie’s use of the word “retard” and what they consider its offensive portrayal of people with intellectual disabilities. ………..

“Our message is pretty clear: We need people with intellectual disabilities portrayed with humanity and dignity,” said Tim Shriver, chairman and CEO of the Special Olympics. “We don’t think it’s fair that this population is singled out.”

http://www.usatoday.com/life/movies/news/2008-08-12-tropic-protests_N.htm