About 8 years ago in Atlanta, I got booted on my first offence, by overstaying in the nearly empty parking lot in midtown by 15 mins (I paid for the hour of parking before that, but the restaurant took their time with the checks). I think "first time offense of being late on your parking by 15 mins - you get a boot" is pretty excessive.
Don't get me wrong, I am totally in favor of parking enforcement, and wouldnt have even been that upset to take the hit and pay the fine. Instead, I had to both pay the fine and wait an hour in that parking lot until someone (working for the boot company) came to unlock the boot on my car (and i was lucky they weren't busy that night).