JUST ADDED: 5 Seconds of Summer will be rocking the stage at this year's iHeartRadio Music Festival Village in Las Vegas! The band sat down with Ryan Seacrest to break the news. Click here to buy your tickets now, before they sell out!
Justin Bieber makes headlines just by existing, so it's no wonder elder people are familiar with who he is. Check out their reactions to a few of the Biebs' headline-making moments below.