The brigid 2014 issue of the Earth First! journal carries an interesting report on a simple method of preventing security/surveillance cameras from seeing your face without having to mask up. These cameras as well as many others
aere sensitive to infra-red light, and you can see inexpensive night-vision security cameras these days with a ring of clear plastic LED diodes around them.
Well, if you buy some of these same infrared (not visible light or “UV”) LED diodes (under $10 worth according to the Earth First! article), put them on a heat, headband, or anything else on your head, cameras see that as bright light but the human eye just sees clear plastic “beads” on a headband! As a result, your face is totally obscured just like shining a bright flashlight at the camera, but you are not obvious to humans in any way.
Most of those facial recognition cameras are just ordinary surveillance cameras hooked up to computers, this technique will jam them cold. Drawing a 3ed eye anywhere on your face is reported elsewhere to confuse the software, which uses the distance between your eyes, plus the distance from them to the tip of your nose as a baseline. A third eye, dark sunglasses, or possibly an eyepatch can throw that out the window. There is also “dazzle makeup” reported to confuse facial recognition cameras.
Although not discussed in the Earth First! journal article, many automatic license plate readers used to track and record movements of drivers in cars use infra-red technology and may be vulnerable to being jammed by bright IR diodes set in a frame surrounding the license plate. As of now laws only prohibit plastic covers or white lights to rear visible to humans beyond what the license plate light makes. Someone needs to TEST this before anyone relies on it, however!