What makes you think there will no longer be zoning laws?
Mainstream is a billboard for Chico's Sophisticated Crank on the I-95. Mainstream is commercials for Stoner's Pot Palace on TV.
Have you seen any billboards or TV ads for cigarettes recently?
Mainstream is a pop-up ad for high-quality needles on Yahoo.com.
It sounds like your biggest concern is having your delicate sensibilities offended.