Rihanna has today overtaken Eminem to become the world’s most popular star on Facebook, according to starcount.com, the social media popularity tracker. At the time of press (4:30pm GMT) the Bajan star stands at 61,564,736 fans (or likes), with Eminem at 61, 217,673, bringing an end to Eminem’s long reign at the top. “Slim Shady”