A photograph of a Master Lock that prevents children from playing video games until a parent enters the secret combination is circulating the internet, landing on the site where all oddities wind up, Reddit. The lock, a steel U-shape that calls to mind the steering wheel club, impedes a game cartridge from being loaded into the system, and was designed to prevent Nintendonitis, according to a 1989 blurb in Entertainment Weekly. Safe Care president Tom Lowe invented the $15.95 device, says the EW report, after hearing that a friends 14-year-old son stayed up all night playing Nintendo instead of studying for finals. Youre a smart child with knack for problem-solving from years spent playing video games.