While I acknowledge that aliens are, by their nature, alien, humans with benign intent don't kidnap, experiment on, and tamper with others. Alien or not, that can be learned without ever touching a human being, just from our own broadcasts. Medical information about humans can easily be gotten from our own public resources, and only one or two persons at most would need to be sampled to learn this and obtain the information sought. The only reasonable conclusion to draw is that - unless it's being done in direct cooperation with any relevant government(s), why they are here isn't immediately relevant since their actions are distinctly hostile. Even allowing for a measure of "they don't understand what they are doing," that fact doesn't excuse their behavior, nor does it abrogate our right, as a species, to defend ourselves from invaders. Yet we have credible (within the UFO framework) military stories that demonstrate that at least some recurrent visitors understand we are able and willing to do them harm.