The Chicago Transit Authority (CTA) has put ads on its trains that pose the riddle, "What do Cubs and Sox fans have in common?"
The answer that the ads supplied was "The Red Line," because both teams' stadiums are located along the CTA's Red Line.
One summer day, when my friend Alma and I were riding the Red Line, we noticed a copy of the ad that had been altered by a grafittist. Just above the CTA's dull answer to "What do Cubs and Sox fans have in common?" was scrawled a replacement answer:
"A PUTZ MAYOR."