“Facebook is in the national spotlight this week as its co-founder and chief executive, Mark Zuckerberg, testifies before Congress. Zuckerberg is expected to face questions from lawmakers over the company’s recent disclosure that data on up to 87 million of its users may have been improperly shared with a political consulting firm during the 2016 U.S. presidential election. His trip to Capitol Hill comes as many Americans express concerns over the way social media firms are handling personal information. Here are five facts about Americans’ use of Facebook, drawn from recent Pew Research Center surveys…”