Untraceable is an enjoyably crappy thriller that makes you ponder the validity of the title. The lead is a single mother who works for the FBI researching Internet crimes, and stumbles upon a site on which a kitten is tortured on a live-feed cam, while the act is being discussed in an adjoining chatroom. Her boss is not too concerned about this and neither will you be, as the kitten looks obviously but unintentionally animatronic. Watching people suffer realistically on-screen is entertainment, but animals would just be cruel. When the little sadist who runs the site moves on to people, a media circus ensues.

His gimmick: the more people visit the site, the faster the people he tortures die. His first victim, for instance, is tied up, cut, and administered fluids by IV drip that keep the blood from clogging, bleeding him dry. The more people watch it, the more fluids he gets — killed by hype and mob mentality.

Tracking the site and pinpointing the origin proves impossible because of some technobabble that the writers of the movie are betting will confuse you, involving switching IPs, servers, bouncy mirrors, and possibly string theory. I was duly at a loss to completely follow the explanation, but wasn't quite buying that a site with a live chat-room could be set up in the way described.

In any case, the killer turns out to be conveniently local and he is in fact revealed early on, turning the film from a who-dunnit into a why-dunnit. Probably not a good idea, as the authorities aren't making much headway and the movie stalls a little until some savvy victims start mouthing clues to the camera while suffering and dying horribly. Now there's discipline for you. These clues are followed to great result, by making major intuitive leaps. And of course the hunt turns personal as the creepy killer turns his attention to the single mother and her daughter.

It is a bumpy road all the way when it comes to believability, both in motivations and logic, but it is all done capably enough to go along for the slightly nauseating ride. The climax is a let-down, as the killer suddenly experiences a major drop in intelligence and makes several bad judgement calls. The final shot of the movie was no doubt intended to be cool, even profound, but alas - it looks goofy and ends things with a laugh.

Untraceable, 2008, 100 min. USA. Director: Gregory Hoblit. Starring: Diane Lane, Billy Burke, Colin Hanks.