There wasn't a problem with Jay-Z the rapper being in the locker room, but it is against NBA policy for Nets minority owner Shawn Carter to be there. NBA personnel are prohibited from being in contact with amateur players until they have declared for the draft. The high-powered Wildcats have a likely pair of lottery picks on their roster as well.
It is believed that it is Jay's relationship with basketball rainmaker William Wesley that led to him being in the room. Wesley, also known as Worldwide Wes, also has a relationship with Kentucky coach and former Nets coach John Calipari. Based on past infractions around the league, Jay-Z will likely face a small fine.
HipHopDX