I wonder if this movie was proposed to the studio bigwigs as: "It's Saw meets Apache Web Server Security!" Maybe.
Diane Lane plays intrepid FBI Agent Jennifer Marsh. Her usual gig has her working the night shift in the Portland, Oregon office, ferreting out cyberscammers with her trusty honeypots, calling in the cops to knock down doors once she's established at-least-semi-probable cause. (Civil libertarians might quibble. Most who have been on the receiving end of internet crooks will cheer, maybe wishing she'd called in an air strike instead.)
Soon enough, though, she's investigating a local serial killer with a new gimmick: he executes his victims on-webcam with elaborate sadistic mechanisms; the more people watch, the quicker the end comes. And—as you might guess from the title—the killer's site is untraceable.
I'll give the screenwriters credit: when they have Jennifer explain the untraceability, they have her use actual network terminology, like "IP address", "TTL", and "name servers" in superficially plausible ways. But—don't worry, folks—if it were that easy, the bad guys actually out there would be doing this sort of thing to Google and Amazon, not piddling around with mass murder.
Also, I don't find it credible that the cops and the FBI can't locate a internet video feed that they know is originating somewhere in Portland.
But never mind. Other than the dubious technical mumbo-jumbo, it's a competent, by-the-numbers cliché-laden thriller. (When a character leaves a message for Jennifer, saying he thinks he has a case-breaking lead, just needs to flesh it out a bit, everyone in the room knew that he wouldn't be having many more lines after that.)