It's just the typical graffiti, "For a good time, call cyrocksmypants, 612-555-1234".
Actually, it's just a small black roundish thingy.
They could at least get my number right if they're promising a good time!
Nah, it was there all season.
The outside of the building is landlord responsibility and the landlord is the city of Minneapolis, so that should explain why it's still there.