Facebook, Twitter and Google say they will send representatives to a Senate Judiciary subcommittee hearing next week on Russian meddling in the 2016 election.
The 31 October hearing is the third scheduled with the social media companies as congressional investigators probe the spread of false news stories and propaganda online. The three companies are already scheduled to testify at Senate and House intelligence committee hearings on the same subject the next day, 1 November.
The Senate intelligence committee announced on 25 October that each company will send its general counsel to testify. That's Facebook's Colin Stretch, Twitter's Sean Edgett and Google's Kent Walker. The companies have confirmed their attendance at the other two hearings but have not yet said who will appear.
All three committees are investigating the Russian interference and whether it is linked to President Donald Trump's campaign. Facebook recently provided all of the committees with more than 3,000 ads they said were seen by an estimated 10 million people.
The ads, which Facebook said were traced to a Russian internet agency, focused on divisive political messages, including LGBT issues, immigration and gun rights.
Legislation proposed by Democratic Sens. Mark Warner of Virginia and Amy Klobuchar of Minnesota would require social media companies to keep public files of election ads and meet the same disclaimer requirements as political broadcast and print advertising. Both Facebook and Twitter have said they will provide more information to the public about political ads, including who is funding them.
Federal regulations now require television and radio stations to make publicly available the details of political ads they air. That includes who runs the ad, when it runs and how much it costs.