Twitter, the president’s favorite form of electronic communication, is flagging 9.9 million accounts a week for suspicious activity as social media firms work to prevent misuse of their platforms before midterm elections in November.

That’s a fourfold increase from the same time a year ago, Nick Pickles, a senior strategist for public policy at the company, told the House Judiciary Committee in a Tuesday hearing where he joined representatives of Google subsidiary YouTube and Mark Zuckerberg’s Facebook.