Works in the same way as a certain batch of Sony camcorders that was released several years ago.
Story goes: Sony released their first "Nightshot" model, several of which had not been fitted with the correct filters. If the user switched on the "Nightshot" function during daylight and then looked at someone the subject would appear as if seen through "X-Ray" eyes, ie unclothed. I had the pleasure of seeing one of these in action and it's actually very similar to the way these work, although the original Sony one was a little clearer in daylight.
Although this technology is not new, it's still a very touchy topic. If you were discovered to be using one, say at a beach, you would no doubt be prosecuted for something like invading a persons privacy.
But good find Juzza.
