Weird. I see a black person (or East Asian person, or Indian person, or Hispanic person) stroll through my neighborhood - which happens several times a day, since they are neighbors - and have no impulse to call the police. Is there something wrong with me? Or something wrong with DU-grade Proggies' stereotype?
Now, if I see a stranger of any skin color closely checking out cars parked along the street, I might call out to them or call the police. It's their behavior, not their skin color.