Hollywood

Dressing up as a pimp and prostitute in order to seek Acorn's help in starting a child sex-slavery ring wasn't Andrew Breitbart's idea. But without the Internet entrepreneur's flair for publicity, the hidden-camera sting might not have produced such impressive results. Within days of his publishing the video exposé, government agencies were cutting ties with the left-wing advocacy and community-organizing group, Congress was voting to end its federal funding, and news organizations were rushing to catch up with a sensational story they had initially resisted or ignored.

James O'Keefe, the 25-year-old aspiring filmmaker who played the pimp in the Acorn meetings, came to Mr. Breitbart in early August with his videos. They showed Mr. O'Keefe and his...