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–red and white cars following victims, vandalism of their homes, snickering by those around them. Identified by some psychologists and psychiatrists as part of an ‘extreme community’ on the Internet that appears to encourage delusional thinking, a growing number of such Web sites are filled with stories from people who say they are victims of mind control and stalking by gangs of government agents. The sites are drawing the concern of mental health professionals and the interest of researchers in psychology and psychiatry.