Frederik Pohl had a series of books (the first one being 'The Other End of Time') which touched on that a bit. The takeaway was that once the aliens involved 'scanned' you through their transport technology, the people THOUGHT they were transported into the aliens' prison but were really just duplicates created, not until later realizing their original selves were still living their old lives. So for those aliens it really was as simple as Ctrl+C/Ctrl+V...