What is the PS4 MTX Key?

The PS4 MTX Key is an upcoming hardware modification for the PS4. It allegedly allows groups of friends to share games between their PS4s with no limitation. In other words, one of your friends buys a (digital) game on the PSN through a shared account, then the whole group can play the game on their own PS4. Playstationhax reports that some PS3/PS4 scene veterans have confirmed the device is legit. The only difference between gamesharing and piracy is that initially, one of the users in the group needs to buy the original game, which can then be shared with a potentially unlimited group of friends.