but wolfgang - though the likely suspects which get "identified" as UFO's (isn't that self-contridictory?) tend not to be objects; or if objects tend not to be flying - they are PERCIEVED as objects that are in flight - thus "Unidentified Flying Object". Whether or not there actually is an object or if that object is flying is irrelevant to that perception though certainly not irrelavent to the question of "visitors".

but that there are unidentified flying objects is fact. That even some of the unidentified flying objects are visiting spacecraft or evidence of non-terrestrial intelligent life is conjecture.