I love this stuff. To my way of thinking, the limitations of the laws of physics and the vastness of space dictates that the probability of life outside of our solar system is virtually 1. At the same time the probability of that life finding and being capable of travel to our solar system is virtually 0. If such life possesses the extreme technological capability of traveling the distances required to reach our solar system it seems highly unlikely they would sneak around in fear of us. Their technical superiority would be beyond our comprehension.
I agree completely. To any civilization capable of coming here, we would be so technologically and probably biologically inferior (especially with regard to brain power) that the difference would be similar to comparing humans with chimpanzees as a minimum. I envision two year old Zichron from planet Zicanios performing third semester integral calculus to entertain himself, giggling as he solved the equations. On the other hand, Zefrem Cochrane will invent warp drive in 2063 in Bozeman Montana, so it might not be that far off for us to get into interstellar and intergalactic space.
And the probability that they are coming in peace is virtually zero
If they were to come here it would be for one of two reasons: 1) because they wanted the planet and humans would just be an annoying sentient organism infesting the world that would be a slight impediment to their taking over or 2) they found us, recognized a civilization in danger of destroying itself and wanted to somehow help us. But to cite history, Columbus coming to the New World was bad for the Indians.
Coming back to reality, a UFO is an unidentified flying object. UNIDENTIFIED is the key word. Being unidentified does not mean it came from outer space.