The Vancouver Sun has been doing a series of articles on the sad story of the "Highway of Tears" in B.C., where several young women have vanished. Today's front page bears this photo as a lead-in to today's installment:
The caption below it says that this billboard "warns girls not to hitchhike on the Highway of Tears..." But without a comma after "girls," the sign actually reads as a statement that "girls don't hitchhike"-- a statement easily disproved by the fate of these unfortunate young women.
I came across a similar case of comma confusion awhile back while reading an entry in Slate's TV Club breakdown of a Mad Men episode. One of the writers was describing an exchange of dialogue where the character of Conrad Hilton supposedly says to our hero, Don Draper, "What do you want from me, love?" I hadn't seen the episode yet when I read that, but to me it seemed out of character for the no-nonsense Hilton to address Don as "love." Of course, when I watched the show later I was able to confirm that what he had really said was, "What do you want from me? Love?"
It just goes to show how that unassuming little twig of punctuation can, whether by addition or omission, create unintended twists of meaning.