These are people who believe—falsely, it is suggested—they are being mind-controlled, mentally stalked, and otherwise tormented by covert and sinister forces. The article draws an analogy between this community and the community of people who, in the 1990's, believed that they had been abducted, and usually sexually stimulated, by aliens.
In each case, an otherwise irrational belief gets support from the fact that other people believe the same thing. The point of the article is that the internet community is encouraging participants to believe that their crazy beliefs—that they are being monitored, watched, manipulated from afar—are true, when in fact they are false.
As a philosopher I couldn't help wondering: So, um, how do we know these people are delusional, and not just, you know, better informed than the rest of us? I mean, it's not impossible that the CIA is conducting ESP experiments on unsuspecting citizens.
The Times tries to find out an answer to this question from the American Psychiatric Association, but it turns out the APA itself is a little hazy on the concept. The Times cites a British psychologist, Dr. Bell:
"The extent of the community, Dr. Bell said, poses a paradox to the traditional way delusion is defined under the diagnostic guidelines of the American Psychiatric Association, which says that if a belief is held by a person’s “culture or subculture,” it is not a delusion. The exception accounts for rituals of religious faith, for example."
Wait. So the fact that these people have found each other online makes them technically less likely to be "deluded"? On the official criteria?
Isn't this a little strange? Sometimes "everyone else thinks so, too" makes you rational and sane and part of a community and sometimes "everyone else thinks so, too" shows everybody is insane?
So the answer to the question, "When is a delusion not a delusion?" is, "When enough people share it with you." It follows from this that the way to make something true is to get enough people to believe in it.
No wonder people make fun of us believers in "reality-based" thinking. What a bunch of chumps we must seem.
Remember kids: just because you're paranoid doesn't mean they're not out to get you.