https://www.recode.net/2017/9/27/16376228/facebook-google-twitter-testify-congress-senate-russia-presidential-election

Senate lawmakers investigating Russian interference in the 2016 presidential election have asked Facebook, Google and Twitter to testify at a Nov. 1 hearing, a source familiar with the matter told Recode on Wednesday.

The inquiry — to be held by the Senate Intelligence Committee — could subject the three tech giants and their executives to uncomfortable questions in the open about the extent to which Kremlin-backed forces may have used their platforms to spread misinformation, and what those companies might have done differently to stop it.