Facebook hopes to stop foreigners from meddling in future US elections by verifying their location via postcard.
The postcards will contain a specific code required if a campaign mentions a specific candidate running for office. It won't be required for issues-based campaigns. Once the buyer receives the postcard, they'll be able to use the code to verify their ad campaign on Facebook.
The plan was announced by a senior company executive on Saturday as part of a wider programme to make its ad policy more transparent.
Facebook was singled out for criticism byaccused of meddling in the 2016 US presidential election. Although it didn't accuse Facebook of any wrongdoing, the indictment detailed the ways it was critical to the trolls' efforts to disrupt the election.
"It won't solve everything," Facebook's global director of policy programs Katie Harbath told Reuters. But Facebook has confirmed to CNET that it considers this the most effective method for weeding out illegal ad buyers.