Safety pin that hold the big pin in place on a hich

I was camped out one time and another couple came by looking for their hitch. They used a safety pin to secure the "big pin". It must have fallen out, because the whole hitch was missing. They gave up the search and spend some big $$ replacing their hitch so they could get home.

Buy a locking pin and use it. They are much easier to install, and can help prevent theft or loss of your hitch.