3 Blind Mice (2003)

Thomas (Edward Furlong) is a young computer specialist who spends most of his (spare ?) time on the net. He logs regularly on Cathy's site and apparently runs a very strong - but platonic! - relationship with her: they only see each other through webcams. One day, while Thomas is connected, Cathy is murdered under his eyes. But when he calls the police to try to "do something" he realizes that he doesn't even now her "real" name or adress.... Apparently the only witness, Thomas will soon find himself involved in the investigation held by Claire (Emilia Fox) a young police officer also web specialist. Together they will discover in the real world as well as in the virtual one, very weird things....