The Facebook CEO is facing a giant tax bill. Analysts say Zuckerberg is expected to owe the IRS more than $1 billion in taxes for 2012. Zuckerberg's whopping tax hit stems from his move last May to increase his stake in Facebook.
On the day of Facebook's Initial Public Offering, Zuckerberg exercised a stock option and purchased 60 million Facebook shares. He later sold about half those shares.
Zuckerberg's paper fortune is currently valued at around $13 billion.
