There is a classic economics example called the prisoner’s dilemma. Picture an episode of Law and Order or the Wire, two criminals in separate interrogation rooms. They are asked to confess to a crime, if they confess they’ll get less jail time, but if somehow they can both manage not to confess both will be better off.
The example is used to show that confessing is better for each individual, but when they both do confess they are worse off. In response to this situation a “stop snitchin’” movement has started up (basically snitchin’ is implementing others in crime). In an economic sense if the “stop snitchin’” movement is powerful enough then confessing may no longer be best for a given individual. The movement includes t-shirts and DVDs. Including the recently released Stop Snitchin’ 2 video, which is being critized by the media and police, here is a link to a youtube preview (the video contains adult language).
Unfortunatly the stop snitchin' movement has a negative effect on members of the community too (article).