Well, not extraterrestrial aliens, but those that believe aliens have been visiting Earth and who all happen to be English.
This is a video from the same series of trying to take strong believers in some subject and try to confront them with experts and their evidences that show their beliefs are demonstrably wrong. I linked to a video before with Jerry Coyne confronting several creationists, and to little effect.
Here, PZ Myers and Michael Shermer, noted scientists and skeptics, try to argue that the things that make UFO conspiracy theorists just don’t hold up. It seemed that PZ actually had the best effect (at least according to the editing), and Shermer did well to make his position more respectable (one woman on the show went from insulting him to respecting him). But, as you may have expected, no luck in convincing these folks overall.
There were some other things strange to me. One of their experts argued that Stalin had flying saucers with disfigured pilots to scare Americans, which isn’t all that likely (a journalist/historian using only one source for so incredible a claim is not going to convince), and polygraphs are not much better than chance in guessing if someone was lying. Nonetheless, entertaining and interesting.
Oh, and they do go to Area 51 and get arrested and their cameras taken!
So, how would you try to convince a believer?