https://www.reuters.com/article/us-usa-trump-russia-facebook/facebook-pressured-to-notify-people-who-saw-russian-posts-idUSKBN1D22X6 >Facebook Inc received several tongue-lashings during U.S. congressional hearings this week, but the world's largest social network also got an assignment: Figure out how to notify tens of millions of Americans who might have been fed Russian propaganda.