Advice was given on how to spot and reject surveillance methods at the Def Con conference.
Phil Polstra, associate professor of digital forensics at Bloomsburg University of Pennsylvania, said that many of the small, hidden cameras on the market these days have infrared lights around their lenses, Polstra said. That light, invisible to the human eye, allows the cameras to keep up the surveillance even in the dark, without getting noticed.
However that light can be detected by smartphone cameras and to see if you’re being watched, turn on the camera and scan it around the room as his demonstration showed that when his phone lens passed an infrared light, a bright purple hue showed up on his phone display, theLA Times reported.
