If they were real, I think our Armed Forces would have shot them down.
I think your right John, we would have shot them down, and learned their technology. We would have had it by now if they existed.
I"m not sure, but after reading the other posts, I'm leaning towards probably not.
I think they are real but I'm sure we (earth) hasn't seen any-yet.
They're probably real but I haven't seen one.