Men in Black, also known as MIB or MIBs, are mysterious characters who reportedly question, threaten and sometimes harass UFO witnesses and researchers. They have been active on the American UFO scene since 1947 but rarely appear in foreign countries. Dressed in black suits and wrap-around sunglasses, MIBs are slender, dark-complexioned men whose facial features have sometimes been described as Oriental. They generally travel in groups of three in large, black automobiles, usually Cadillacs. They pose as FBI or CIA agents, military personnel, insurance brokers and telephone inspectors. Researchers who accept the existence of MIBs conclude that they are either a secret government agents or extraterrestrials living on Earth. The most famous case involving MIBs was that of investigator and author Albert K. Bender, who was reportedly silenced by three men in black in 1953.