https://finance.yahoo.com/news/facebook-plans-u-mail-verify-205341300.html

Facebook revealed the plans a day after U.S. Special Counsel Robert Mueller unsealed an indictment accusing 13 Russians and three Russian companies of conducting a criminal and espionage conspiracy using social media to interfere in the election by boosting Republican Donald Trump and denigrating Democratic candidate Hillary Clinton.

The process of using postcards containing a specific code will be required for advertising that mentions a specific candidate running for a federal office, Katie Harbath, Facebook's global director of policy programs, said. The requirement will not apply to issue-based political ads, she said.