Cry_Wolf (2005) on Netflix

Eight unsuspecting high school seniors playing a game of lies come face-to-face with terror and learn that nobody believes a liar - even when they're telling the truth. After one too many incidents of bad behavior at his last school, Owen Matthews arrives at Westlake Prep - where a young woman has recently been found murdered in the dark woods near the boarding school's campus. Owen quickly falls in with the school's unofficial "liar's club," including the beautiful and savvy Dodger and quick-talking, short-tempered Tom. At Owen's suggestion, his new friends decide to expand their game's reach beyond campus, by spreading an on-line rumor that a serial killer called "The Wolf" committed the recent murder and is planning to strike again. The mischievous group's descriptions of "The Wolf's" intended victims are based on the people they know best - each other. Only when the school's journalism teacher, Rich Walker, warns the group about the kinds of predators that lurk on the Internet does Owen begin to regret sending their falsified story into cyberspace. When the described "victims" suddenly start to disappear, Owen, Dodger, and Tom are no longer able to determine where the lies end and the truth begins. As someone - or something - starts hunting the players themselves, the game turns terrifyingly real.