DON`T mess with JUSTIN BIEBER. The teen titan has wreaked vengeance on a hacker who leaked his phone number online. Michigan-based Kevin Kristopik broke into JB`s social media accounts and leaked his digits earlier this week. But the cunning little fella hit back by unearthing Kev`s number and posting it for his 4.5million followers to see. He claimed they were his own and invited fans to ring him. Justin wrote: "Everyone call me 248-(Kristopik`s number) or text." He took the post down within minutes but Kevin`s line had already been jammed with calls. Kevin later Tweeted: "@justinbieber is a d***".