Steven Spielberg is legendary in the film industry. He produced blockbusters such as JAWS, Close Encounters of the Third Kind and ET among his many successes. It was even said that during the making of Close Encounters a character in the movie was actually modeled after Jacques Valle, the UFO Researcher. According to Mr. Spielberg he has not personally witnessed a UFO but is a believer, and furthermore thinks disclosure by the government should occur and wrote a letter saying so. You can find this interesting article with the letter HERE.