There’s some serious suggestions from more than a few diverse sources that something very close to that has been designed to be the case. That implants that render humans passive, compliant slaves at a given future technological switch thrown or signal sent . . . are now likely planted in upwards of 3,000,0000 Americans alone.
Here you have some of the reasons I have for not finding the stories of massive numbers of human abduction stories. An advanced interstellar traveling race would not need to abduct more than a few humans to gather the info necessary to manufacture a virus or perhaps nano machines that could do all of the things which implants might do.
With a custom designed virus or self replicating nano machines infection of a handful of humans strategically placed around the world in a few months nearly the entire world would be infected.
Why bother abducting huge numbers of individuals?