»18th and Valencia / Steiner

Walking past the vacant lot at the corner of the 18th and Valencia, I saw a woman stooping to scoop the poop her dog left along the chainlink fence. As she stooped, a voice said, "You don't need to clean that up." (You do.) The voice came from a disheveled young man sitting on the sidewalk, a few feet away from the poop. This photograph, misleadingly, is from Steiner between Haight and Waller.

New York City's famous 1978 Pooper Scooper law certainly set a standard, but how and why is it more well-enforced than similar laws in San Francisco?
On a related note, the fine folks at Blue Bottle Coffee note that even new developments in San Francisco are prone to mediaeval nastiness: "Some time between Thanksgiving 2007 and the closing ceremonies of the Beijing Olympic Games, we will be opening our first café! We will be opening on a formerly pee-smelling alley on the corner of Mint and Jessie in downtown San Francisco now excitingly called Mint Plaza. We will be serving toast, a few snacks, maybe a glass of wine in the evening. Oh, and coffee." Mint Plaza, once a Golden Gate Transit turnaround, now an urban oasis!

Note: two years earlier, during the same large event in San Francisco, another New Yorker made a similar observation.