Men in Black

The MIB, a top-secret agency that polices, monitors and directs alien activity on Earth, has established the Earth as an apolitical "neutral zone" for alien refugees. MIB agents have no identity or any public record of existence, and the MIB agency answers to no government. The funding for their agency comes from the patents they own on technology confiscated from aliens, such as velcro, microwave ovens, and liposuction. Any memory of MIB activity upon "mustering out" of the MIB is erased and a new identity is created for the departing agent.

MIB agents wear sunglasses and dark suits, and appear at UFO landing sites. Since the MIB are a secret organization, no evidence of their existence can be left. Instead of intimidating or threatening witnesses, the MIB use devices known as "Neuralyzers" to wipe witnesses' memories of what they have seen, and replace the memories with more mundane explanations, such as swamp gas or weather balloons. Neuralyzers are also used on agents who leave the organization for any reason. The MIB's sunglasses protect them from the effects of the Neuralyzer. Agents drive around in a seemingly inconspicuous black car, a 1987 Ford LTD Crown Victoria, which, with the press of a red button on the gear stick transforms into a high-speed rocket-propelled car. - edited from wikipedia