Facebook is censoring marijuana.

Just last week, the social networking giant abruptly changed its policies and decided to ban images of marijuana leaves from ads, claiming pictures of the plant promote “tobacco products.”

Just Say Now, our campaign for marijuana legalization with Students for Sensible Drug Policy, ran ads promoting our campaign that showed our logo, which uses a marijuana leaf. Despite the ad running more than 38 million times, Facebook flip-flopped and started censoring our ads and our political speech.

We’re fighting back against Facebook’s censorhip with a massive campaign to call out the social networking site.

Sign our petition to Facebook to protest censoring marijuana as political speech. We’ll send the petition to Facebook and call attention to the popular support for opening a discussion about our country’s failed drug policies.

Ryan Grim at Huffington Post has more on the story:

For a typical college student, if it didn’t happen on Facebook, it didn’t happen. That gives the social networking behemoth an out-sized influence on the confines of political debate, if that debate falls outside what Facebook deems acceptable discourse. Proponents of marijuana legalization, which is on the California ballot in 2010, have hit a Facebook wall in their effort to grow an online campaign to rethink the nation’s pot laws. Facebook initially accepted ads from the group Just Say Now, running them from August 7 to August 16, generating 38 million impressions and helping the group’s fan page grow to over 6,000 members. But then they were abruptly removed. Adam Noyes, a spokesman for Facebook, said that the problem was the pot leaf. “It would be fine to note that you were informed by Facebook that the image in question was no long[er] acceptable for use in Facebook ads. The image of a pot leaf is classified with all smoking products and therefore is not acceptable under our policies,” he told the group in an email, which was provided to HuffPost.

Just what kind of devious, subversive ad ran 38 million times on Facebook? See for yourself. These are the ads Facebook saw fit to censor: