Lisa

Fourteen year-old Lisa is raised by her unmarried mother Katherine who overprotects her by forbidding her to date until she's sixteen. In despair, Lisa and schoolmate Wendy make up a game that consists of inferring attractive men's phone numbers from their car ID and giving them anonymous calls. Last victim is the handsome Richard, with whom Lisa begins a passionate phone relationship, unaware that he's also a psycho-killer and sex maniac... (imdb)