dryriver writes: CNN reports: Police find an advert for paid sex online. Its an illegally trafficked underage girl posing provocatively in a Hotel room. But police doesn't know where this hotel room is — what city, what neighborhood, what hotel or hotel room. This is where the TraffickCam phone app comes in. When you are staying at a hotel, you take pictures of your room with it. The app logs the GPS data (location of the hotel) and also analyzes what is in the picture — the furniture, bedsheets, carpet and other visual features. This makes the hotel room identifiable. Now when Police come across a sex trafficking picture online, there is a database of images that may reveal which hotel room the picture was taken in. About 100,000 people have downloaded TraffickCam so far.