To be sure, the Los Angeles Police Department maintains that it is mapping Muslim neighborhoods to help their residents, not arrest them. The idea is to identify hot spots of discontent where extremism might grow, and then to increase social services to those neighborhoods in order to combat radicalization.

In principle, this strategy is sensible. But the residents of these neighborhoods have already seen six years of suspicion and scrutiny, and they are not likely to appreciate the principle. They're likely to see the mapping project as a prelude not to assistance but to repression.

Neighborhood mapping sounds Giuliani-esque to me. That's not surprising, since the LAPD Commissioner is Bill Bratton, who was the architect of New York City's crime reduction plan under Giuliani which used similar mapping tactics. But in New York they went after crime hot spots, not Muslim residential hot spots. This plan is awful and sets a dangerous precedent.