"Most law enforcement agents can do their jobs with a black and white moral outlook. Undercover agents have no such luxury. An undercover agent must sound, look and most importantly act like a criminal so undercover work is an exercise in morally murky decision making. Undercover agents are constantly wrestling with what actions they can and must do to maintain their cover identity and stay alive. Popular cinema has done its best to try and capture some of these pivotal moments of undercover law enforcers doing the unethical and unthinkable in order to stay alive and take down their target."................. More info here.