Singer Justin Bieber has fallen fowl of traffic police again after reportedly failing to produce a valid California licence after he was pulled over on Wednesday (28Aug13) for driving through a stop sign. Cops stopped the pop superstar, who was driving a Ferrari sportscar near his home in Calabasas, and asked to see his licence. According to TMZ.com, Bieber was co-operative as the officers issued him a ticket for running a stop sign. He was also cited for being unlicensed and the cops insisted his unnamed passenger had to take over the wheel and drive the pop star home. Reports suggest the Never Say Never hitmaker moved to California in June (13) and has failed to obtain a state driver's licence. By law, new residents must pick up fresh driving documents within 10 days of a relocation.