On Tuesday, Facebook CEO Mark Zuckerberg testified before Congress. Shares of Facebook recorded their best day in two years. On Wednesday, Zuckerberg continued his testimony. Motley Fool analysts Matt Argersinger and David Kretzmann weigh in on what it means for investors and discuss the implications for other big tech stocks. Thanks to Slack for supporting Motley Fool.  Slack: Where work happens. Go to slack.com to learn more.