Justin Bieber is a teen mega superstar, but is his head getting to big? Recently Bieber made two appearances on the TV show "CSI" playing a troubled teen, It seemed that he kept the role going after they stopped shooting.  Co-star Marg Helgenberg said Bieber was acting as a jokster and very childish.

"I shouldn't be saying this but he was kind of a brat,” she said. "He was very nice to me. But he locked one of the producers in a closet and he put his fist through a cake that was on the cast's table." www.celebritycafe.com