This does not work for FR that does not observe IR. Which is most FR systems, because most FR systems have to use legacy video hardware several years, often a few camera generations, back. Including wholly optical CCD systems.

However, a similar fashion accessory does an even better job: some fashion hats have blinky LEDs on them; blinky LEDs cause a camera's components to adjustment for the unusually bright light, which are then gone, than back again. The mechanism in most security cameras cannot adjust for the lighting changes as fast as the LEDs are blinking, causing no good captures of the face beneath the blinkly LEDs.