Not for much longer they don't. If anyone thinks this decision will come down on the side of the citizenry and not the gov't apparatchiks, they're smoking crack.
Even if the SCOTUS overturns the law in DC, the other large cities that effectively prohibit gun ownership, like Chicago, will never rescind their draconian laws. It's over, man.
Frisco is the only other large city to attempt a handgun ban, IIRC, and the Cali Supreme Court just shot that down not long ago. Some towns in Chicago's suburbs also have bans. If D.C.'s bans goes down as violating an individual right, Chicago's and the others will follow.