I snapped one the other week. I seriously thought I was the strongest eprson alive when I did this.
I was on the flats, on a recovery ride after a race, and I stepped a little hard on the pedals, and the Super-Duper pin that it comes with snapped right in the middle. Granted, the chain had 3,500-4,000 miles on it, but it shouldn't have broken like that. One half of the pin was still inside of the chain.
I'd like to tihnk I'm that powerful.