For people who regularly visit and write on message boards on the mind-control sites, the idea that others would describe the sites as promoting delusional and psychotic thinking is simply evidence of a cover-up of the truth.

“It was a big relief to find the community,” said Derrick Robinson, 55, a janitor in Cincinnati and president of Freedom from Covert Harassment and Surveillance, a group that claims several hundred regular users of its Web site. “I felt that maybe there were others, but I wasn’t real sure until I did find this community,” Mr. Robinson said.

There is no concise survey of mind-control sites or others describing gang stalking  whose users believe that groups of people are following and controlling them, as part of a test of neurological or other kinds of weapons likely conducted by the government  on the Net. But they are easy to find. Some have hundreds of postings, along with links to dozers of similar sties. One, Gangstalkingworld.com, welcomes visitors with this description: “Gang Stalking is a systemic form of control, which seeks to destroy every aspect of a Targeted Individual’s life. The target is followed around and placed under surveillance by Civilian Spies/Snitches 24/7.”

The site lists more than 71,000 visitors, and it has links to several other sites, including Harrassment101.com, which has 965 posts.

One poster to Gang Stalking World wrote in August: “It’s insane that I daily have to come home and try to figure out if my Web sites will still be up or shut down. This week they have really been playing with me, and so it was my time to play back.” The post directs readers to other gang-stalking sites should their favorite sites be shut down.

Mr. Robinson said in an interview that that he has been tortured and abused by gang stalkers and by “neurological weaponry” since leaving the Navy in 1982. “To read the stories and the similarity of the harassment techniques that were going on, to hear about the vandalism, appliance tampering and all the other things were designed to drive a person crazy, who do you go to with this?” he said. “People will say you are delusional.”