The FBI is also used by various organizations to investigate various crimes, whether real or not. For instance, the Bureau of Industry and Security thought my company was flaunting export regulations and had the FBI raid my company to investigate. It turned out to largely be due to a paperwork problem, but the BIS didn't have the power to investigate so they contracted the FBI to provide the manpower to do the raid. So who we saw was the FBI, but it was really the BIS originating the raid.