LOS ANGELES, CA - FEBRUARY 20: Singer Rihanna during the 2011 NBA All-Star game at Staples Center on February 20, 2011 in Los Angeles, California. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. (Photo by Kevork Djansezian/Getty Images)

LOS ANGELES, CA - FEBRUARY 20: Singer Justin Bieber (L) and musician Lenny Kravitz speak during the 2011 NBA All-Star game at Staples Center on February 20, 2011 in Los Angeles, California. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. (Photo by Noel Vasquez/Getty Images)

Canadian singer Justin Bieber signs an autograph on a basketball before the start of the NBA All-Star basketball game in Los Angeles February 20, 2011. REUTERS/Danny Moloshok (UNITED STATES - Tags: SPORT BASKETBALL ENTERTAINMENT)