https://techcrunch.com/2018/02/18/facebook-will-verify-the-location-of-u-s-election-ad-buyers-by-mailing-them-postcards/

Facebook’s global director of policy programs says it will start sending postcards by snail mail to verify buyers of ads related to United States elections. Katie Harbath, who described the plan at a conference held by the National Association of Secretaries of State this weekend, didn’t reveal when the program will start, but told Reuters that it would be before the Congressional midterm elections in November.

The cards will be sent to people who want to purchase ads that mention candidates running for federal offices, but not issue-based political ads, Harbath said, and contain a code that buyers need to enter to verify that they are in the U.S. The program is similar to ones used by Google My Business and Nextdoor when they need to verify business owners or users who want to join closed neighborhood groups, respectively.