A twist on the old idea of the strap lock. Dunlop's Ergo Strap Lock is a one-piece locking device that you simply slip over the existing strap pin on your guitar (with the strap in place) and just give it a twist to keep your guitar securely in place. There's no need for extra hardware.
Hardcore protection doesn't have to mean modifying your guitar. Attach your strap as usual, then place the Ergo Strap Lock over the strap button so that the head of the button extends through the "keyhole" in the strap lock. Then just rotate the circular locking plate 180 degrees