While driving last night from Wellesley to Charlottesville, I was stopped for not having a working light over the rear license plate.

My wife said, "It makes sense to have such a rule; otherwise police could not read your license (at night)."

My response was, "Why do the police need to read my license plate (at night or otherwise)?  Why require license plates at all?"

The answer is presumably something like, "It helps police solve crimes." 

But how many?  Is it worth the cost of all those license plates?