More than half of the top 50 highest-grossing films in 2012 featured a low humming noise in their audio tracks—on purpose. Anti-piracy company Verance Corp. is being hired by more and more Hollywood studios to place audio watermarks in their big films, The Wall Street Journal reports.
The buzzing sound, inaudible to movie goers (it just becomes white noise under the regular soundtrack of the film) can be picked up by the tiniest of microphones. So when moviegoers use a cellphone or camcorder to copy the film, and then burn it to a DVD, their bootleg has the watermark as well. The noise is a signal to Blu-ray enabled DVD players—which are now present in around one in four US homes— that the movie has been copied illegally, and the devices respond by shutting down. Standard DVD playing devices can’t detect the noise.
But here’s the crazy part: Instead of turning the movie off right away, Blu-ray players are signaled to go dark 20 minutes in. That’s because studios want viewers to be just engrossed enough to agree to pay for a legal copy. After the 20 minute mark, the Blu-ray player offers you paid download options—or, if the movie is still in theaters, options for pre-ordering it. But since video streaming outpaced DVD views last year anyway, let’s see how many of those teased viewers just set sail for The Pirate Bay.