But it must not have been PG-13 enough. The MPAA and Warner Bros have demanded that the trailer be pulled from all theaters.
Slashfilm obtained a copy of the letter sent to theaters, which states (emphasis theirs):
"Warner Bros. and the M.P.A.A. have instructed all theatres to remove The Hangover Part II trailer #2 from Source Code and any other placements. These #2 trailers need to be DELETED FROM YOUR SERVER." adding: "We greatly appreciate your immediate cooperation on this matter."