Jared Leto and Skrillex became friends during their days fronting alternative/emo groups 30 Seconds To Mars and From First To Last respectively. They've remained best buddies ever since, even as they've both become megastars. Skrillex is now one of the biggest DJs on the planet, while Jared is a Hollywood star who was hand-picked to the play the next incarnation of The Joker. You don't necessarily have to be a fan of both if you're a fan of Skrillex, of course, but his audience knows that Jared is an important part of his life.