"SAN FRANCISCO A recent Supreme Court decision could alter what public transit riders here see in advertisements on city buses and trains and in transit shelters.
"Despite a San Francisco Metropolitan Transportation Agency policy prohibiting advertisements that appear to promote the use of firearms, a gun rights group's posters have been placed in city bus shelters.
"Images promoting guns, which are banned under an advertising policy of the San Francisco Metropolitan Transportation Agency, showed up recently on posters for a conference for the Second Amendment Foundation, a gun rights group based in Washington.
"The group spent some $10,000 to have the posters, which feature a woman armed with a shotgun, hung at bus stops across the city. The poster's red type reads, A violent criminal is breaking through your front door. Can you afford to be unarmed?"