 When these devices were introduced to the United States and Europe, video game enthusiasts quickly started swapping the copied games over bulletin board systems.Release groups formed to cater to the need of fresh games, and also to crack the protection that was employed to thwart copying in several games released after copiers became available.Release groups would also add their own intros to games, to advertise their BBSes and new releases, and sometimes include a trainer to optionally start on later stages or with more lives.