Social media platforms are capturing a growing share of political advertising in the US and the revelation that Russian interests used Facebook to influence the presidential election are stirring calls for greater transparency.
Television stations, cable and satellite companies and radio stations all must keep records of and disclose who pays for political messages on their outlets, how much they paid, and when the ads aired. As early as 1927, Congress passed a law barring radio stations from broadcasting any ad that didn’t identify its sponsor.