Researchers from Australia's Sydney University have hit a snag during their latest project on medical cannabis, discovering one of the major recruitment tools used for previous studies won't allow any of their advertisements.
That tool? Facebook.
The researchers are attempting a 2018 version of their 2016 Cannabis as Medicine Survey (CAMS16). In 2016, over 80% of respondents to the survey came via Facebook.
"Facebook was a huge part of our recruitment," Nicholas Lintzeris, an addiction medicine specialist and professor at Sydney University told BuzzFeed News.
In 2016, one of the project's investigators used their personal account to share the study in as many groups and corners of Facebook as possible. This year, the university decided to try Facebook advertising, however the ads are being rejected. They say efforts to fight the rejection have been met with silence.
Advertisements for cannabis-related content are blocked by Facebook for violating the site's community standards, and for running foul of an algorithm that blocks terms such as "cannabis".
"We've played around with every search term under the sun to get around it," said Lintzeris. "As soon as you have any key words like THC, marijuana or cannabis things get tricky. There's only limited ways you can refer to it."
There have been rumours for years that Facebook has been shadow-banning cannabis – and any terms related to the drug – on its platform.
Searches on Facebook using key words like "weed", "marijuana", and "cannabis" don't return much other than well-established weed-focused publications.
Earlier this year, even California's Bureau of Cannabis Control wasn't showing up in search.
Wow. Facebook is shadow-banning @BCCinfo_dca, the California state agency regulating cannabis, putting it on the same level as InfoWars. https://t.co/rFipqeWSSa
On the eve of Canada legalising recreational cannabis earlier this month, Facebook told MarketWatch it would be ending its block on cannabis search results for pages that carry verification symbols.
“When searching ‘cannabis’ or ‘marijuana,’ Pages that have been verified for authenticity will now be included in search results," said Facebook spokesperson Sarah Pollack.
"We are constantly working to improve our search results so that we minimise the opportunity for people to attempt illicit drug sales, while showing content that is allowed on Facebook and is relevant to what you are searching."
Many cannabis influencers, reviewers, and fanatics have already moved away from the platform, due in large part to the perceived key word search block. On YouTube a similar phenomenon occurred, leading to creators with tens of thousands of subscribers turning to their own, weed-friendly platforms such as WeedTube.
The researchers at Sydney University hope their 2018 survey can show how the legalisation of medical cannabis in Australia has affected the public's knowledge on the topic.
"We want to continue to get a mix of people that are still illicit cannabis users and we want to do a snapshot of what's going on out there in the community," said Lintzeris.
Lintzeris said using Facebook as a way to gain participants for the anonymous survey allowed researchers access to hidden populations.
A Facebook spokesperson told BuzzFeed News that two ads from the research team were mistakenly rejected by the platform's ad verification systems. "This was due to the ads including terms referring to restricted goods, and the linked content referring to usage of restricted goods," said the spokesperson.
Facebook went on to approve both ads, but neither were ever active as the end date marked by the university had lapsed. An attempt to re-run the ads was rejected on Thursday afternoon.
"We tried to do it the right way this time by setting up a page and then paying for ads," said Anastasia Suraev, a clinical research officer involved in the study.
"I wrote up the ad and made sure there was no cannabis imagery and made sure not to use slang terms. But we still got rejected, every time."
Suraev said she wrote to Facebook explaining that it was legal to prescribe medical cannabis in Australia, that the study was being done by the university, and that the survey was interested in the medical side of the drug.
"I didn't get a reply," she said. "Just a rejection."