While the odd drunk or other soul may have had an emergency, the map is more about folks who don't have a toilet, period. According to the SF Weekly, the map (graphically) reflects the city's problems with limited, filthy public restrooms and lack of services for the homeless. So while it's amusing for non-residents and disgusting for city center dwellers or tourists, it did make me think: "Where would I go in public if I had no choice?"