Billboards in favor of marijuana's legalization have begun to appear in Broward County, Florida, and what's unique about them is that they're targeting senior citizens.

"Legalize Marijuana," one says in bold lettering, "I'm a patient, not a criminal." Another reads "Reschedule Medical Marijuana, one of the safest therapeutically active substances known to man."

The billboards are the work of 69 year old Robert Platshorn. According to CBS Miami, not all the residents are happy about Platshorn's billboards. Zed Castro, one of the residents interviewed by CBS' Cynthia Demos, calls it a "gateway drug."

Platshorn spent 30 years in prison for smuggling marijuana. He doesn't want other people going to jail for "not committing a crime," so he's trying to legalize it. In his time out of prison, Platshorn has started "The Silver Tour," which seeks to educate seniors about marijuana's benefits.

Platshorn also plans on using his past as a TV pitchman to put together a 30-minute infomercial on the topic.

"It’s the best way to get our message out and really educate the senior population on how they can live a more comfortable life and stop relying on pills," Platshorn told CBS.