Type mind control" or "gang stalking" into Google, and Web sites appear that describe cases of persecution, both psychological and physical, related with the same minute details. "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. Mr. Robinson's site, Freedomfchs.com ... says its mission is to seek justice for those singled out by "organized stalking and electromagnetic torture." For people who say they are the target of mind control or gang stalking, there may be enough evidence in the scientific literature to fan their beliefs. Many sites point to MK-ULTRA, the code name for a covert C.I.A. mind-control and chemical interrogation program begun in the 1950s. And the users of some sites have found the support of Jim Guest, a Republican state representative in Missouri, who wrote last year to his fellow legislators calling for an investigation into the claims of those who say they are being tortured by mind control. "I've had enough calls, some from credible people - professors - being targeted by nonlethal weapons," Mr. Guest said in a telephone interview, adding that nothing came of his request for a legislative investigation. "They become psychologically affected by it. They have trouble sleeping at night." He added: "I believe there are people who have been targeted by this."