Do Not Enter: Use of Deadly Force Authorized: Area 51 Large Sticker – is perfect for anyone who knows about the strange restrictions at the Groom Lake facility. Area 51 is best-known for housing UFOs by the military. Of course, the U.S. Government denies these allegations, instead claiming that the base is used by the Central Intelligence Agency (CIA) for testing spy aircraft. True or not, deadly force is authorized against trespassers. This sticker is a great way to let anyone know you mean business. Get yours now.