Politico reports: Facebook has been happy to keep congressional investigators focused on the Russian-bought online ads that helped sway voters in last year’s election — despite the many other ways that fake messages and bogus accounts spread on the dark side of social media.

But that may be about to end: Facebook, Twitter and Google are preparing for hearings this week at which lawmakers are expected to grill the companies about the broad reach that foreign actors achieved through fake accounts and deliberate misinformation, a topic that encompasses far more than the 3,000 paid political ads that Facebook disclosed last month.

Some lawmakers are already pressing for more details about so-called organic content, including unpaid posts from thousands of fake, automated and hijacked user accounts. Those questions could require Facebook to divulge more details about the priceless proprietary algorithms it uses to decide what messages its users see. [Continue reading…]