Hahah, very clever idea someone had there. Of course, DIYers and LBYM guys like me (and you, JoeWras) will just use electrical tape cut to the right size, but something like this could be useful as a travel accessory. I can't count how many times I've turned the lights out in a hotel room or Airbnb only to be ambushed by a piercing green LED light coming from the TV or cable modem across the room!
The absolute worst use of an irritating and unnecessary LED light has got to be in an air purifier I bought years ago. I use it at night in my bedroom to provide gentle air circulation and white noise, but there is NO WAY to disable the blue LED lights mounted just under the top control panel. Even covered with electrical tape, the blue light seeps out through the small openings in the plastic grill!
It boggles the mind that not only did they make the LEDs always-on, they used blue ones!