Passage: On May 15, 2008, Six Flags Great America and Six Flags Great Adventure theme parks opened The Dark Knight Coaster roller coaster, which cost US$7.5 million to develop and which simulates being stalked by the Joker. Mattel produced toys and games for The Dark Knight, action figures, role play costumes, board games, puzzles, and a special-edition UNO card game, which began commercial distribution in June 2008.Warner Bros. devoted six months to an anti-infringement strategy that involved tracking the people who had a pre-release copy of the film at any one time. Shipping and delivery schedules were also staggered and spot checks were carried out both domestically and overseas to ensure illegal copying of the film was not taking place in cinemas. An unlicensed copy was released on the web about 38 hours after the film's release. BitTorrent search engine The Pirate Bay taunted the movie industry over its ability to provide the movie free, replacing its logo with a taunting message.Pandemic Studios was developing a tie-in video game adaptation, Batman: The Dark Knight. However, its development faced a series of disruptions and was canceled before completion.

Question: What was staggered to make sure Illegal copies weren't taking place
Shipping and delivery schedules