Facebook is threatening to sue an Israeli entrepreneur named Mark Zuckerberg. This Mark Zuckerberg changed his name from Rotem Guez. Guez legally changed his name on December 7th. Guez (Zuckerberg) has a website called MarkZuckerbergOfficial.com. Guez (Zuckerberg) filed a lawsuit against Facebook in January after the social network refused to give him access to his profile.