Mark Zuckerberg in the Hot Seat and 'Grand Theft Auto' Beats 'Star Wars'! 3 Things to Know Today.Stay in the know in 60 seconds.

1. Today is Mark Zuckerberg's first day in the hot seat, as he is scheduled to testify before the Senate Judiciary Committee and the Senate Committee on Commerce, Science and Transportation this afternoon.Zuck's prepared testimonydoesn't reveal much that we hadn't already learned about Cambridge Analytica and Russian election interference, but everyone will be watching how he handles the grilling.
2. Today is Equal Pay Day. A new survey from CareerBuilder found68 percent of women believethey are paid the same amount as men at their company with a similar professional background. However, according to the U.S. Census Bureau, women still earnalmost 20 percent lessthan men on average.
3. And the video game "Grand Theft Auto V" has mademore money than any movie. The 2013 installment of the popular open world game franchise has sold 90 million units, raking in $6 billion to date.

Watch the previous 3 Things to Know video:Facebook Freakout, Tony Robbins Apologizes and Do You Have What It Takes to Make Coffee for Elon Musk? 3 Things to Know Today.