The San Francisco Municipal Transportation Agency has banned movie ads displaying guns:
While the official poster for the film [The Other Guys] features a maniacal Ferrell and the menacing Wahlberg sailing through the air, guns drawn, the version in Muni stations features Ferrell brandishing a vial of pepper spray and Wahlberg relying upon his bare fists. This is not a coincidence.
Eugene Volokh finds the policy unconstitutional.
The Dish 