Via Quora, how, with a couple dollars and a few spare minutes, to make yourself invisible to Big Brother:
Most cameras (especially black and white security cameras) will see low levels of infrared light. This helps them video at dusk/dawn and in lower levels of light. To test this theory turn on your video camera and point your TV remote control at it. Change a few channels and you will see a pulse of light flash that the naked eye obviously can’t see.
With that said you can easily make an infrared hat with cheap $1 infrared LEDs stitched into the front of the hat, the more the better… Attach a 9 volt battery to the LEDS and bam you are now a giant LED flash light. People will see nothing out of the ordinary, but CCTV cameras will only see a large flash of infrared light coming from your head, hiding your face.