Whats your opinion or idea?
I think there is enough testimony to suggest it is happening, the fire in the sky case is a good example, of the sort of testimony i refer to (whether or not its true is always going to be debatable)
In addition we do it ourselves, to the lessor species here, we dont give a second thought to abductiong other bioforms and experimenting on them, we also use deliberate deception as a means of facilitating this.
Its all speculation, some say none, some say a few, some say many, and some even say everyone gets abducted at least 3 times in their lives.
If time travel is involved (and they often show images of the future, and earths destruction) then the answer may be even more convoluted.
the trend seems to be abduction while young, tapering off as you get older, this makes sense if you are collecting genetic samples, since our genes get damaged as we get older.
If time travel is part of the scenario, its even possible that one of the greys abducting someone is actually themself, from a point "uptime" after their death, nipping back to harvest the necessary genetic samples to build a new clone vessel for themselves, using your own DNA to create a clone body makes sense, perhaps the conciousness rejects tissue thats not from its original bioform