I read The Scarlet Letter in school.  Granted, it's been more than 20 years since then, but I remember that when used as a punitive system public humiliation can have unintended consequences.

From The Seattle Times:

Sen. Mike Carrell is sponsoring a bill that would require people convicted of drunken driving to put fluorescent-yellow license plates on their cars for one year.

My gut reaction was "sure, why not," but then I started thinking about it a little more. Could this simply be a modern (aka: humane) method of inflicting mob justice?

~tod