You know I never thought of this before, but even though it didn't look like a threat, I found more info, where was homeland security, for all we know it could be spraying chemicals all over the valley, here is more info I got;

The UFO hovered 10-15 feet off the ground in front of the FBI building before landing on the roof of the telecom's operations building. Then it cruised slowly over the Federal office building on it's way to the Questar gas offices. The Salt Lake Air Traffic control tower said they didn’t pick up the object on radar and had no knowledge of the craft. According to KUTV news, it "appeared to be 100 feet long", but to this reporter it appeared much smaller, perhaps 20 feet long and 2 feet in diameter. Could this be a shape-shifting craft?

The object had what appeared to be a propulsion system in it's tail end, but the mechanism was not moving....[Because the "UFO" was actually a toy blimp that ran out of battery.]