A documentary film investigating a notorious event in which an art student killed, cooked, and ate a cat on camera in the name of artistic expression has provoked a steady stream of angry e-mails and phone calls ever since the Toronto International Film Festival programmed it as part of its Real to Reel program. But according to TIFF organizers, the protesters have now crossed the line, with one festival programmer receiving a vicious death threat on his cell phone this week. Toronto police are now actively pursuing the caller, and the festival insists that the film will go on as scheduled.