Baltimore police, enforcing the mandatory curfew that went into effect Tuesday night, are dizzyingly efficient.

Short-fused Chicago Mayor Rahm Emanuel has formally decreed that all children below the age of 12 must be off the streets by 8:30 p.m. on school nights, and 9 p.m. on Fridays and Saturdays, saying, "It brings a level of responsibility and accountability to our streets and in our homes."