From the Examiner:

D.C. police will seal off entire neighborhoods, set up checkpoints and kick out strangers under a new program that D.C. officials hope will help them rescue the city from its out-of-control violence.

Under an executive order expected to be announced today, police Chief Cathy L. Lanier will have the authority to designate "Neighborhood Safety Zones." At least six officers will man cordons around those zones and demand identification from people coming in and out of them. Anyone who doesn't live there, work there or have "legitimate reason" to be there will be sent away or face arrest, documents obtained by The Examiner show....

I'm on the road, and can't say much in detail about this right now, but I see no way this could be legal. Thanks to Kris Baumann for the pointer.