Sorry, I tried to say 2 things: 1. Your simple solution: add a 5 second delay after each failed attempt per username OR ip address. 2. It seems that sites that

Sorry, I tried to say 2 things: 1. Your simple solution: add a 5 second delay after each failed attempt per username OR ip address. 2. It seems that sites that do account lock-outs don't suffer from DOS attacks, for some reason.