"I don't think you get it," said Sen. Dianne Feinstein, D-Calif., whose home state includes the headquarters for Facebook, Google and Twitter. "What we're talking about is a cataclysmic change. What we're talking about is the beginning of cyberwarfare. What we're talking about is a major foreign power with sophistication and ability to involve themselves in a presidential election and sow conflict and discontent all over this country. We are not going to go away, gentlemen. And this is a very big deal."