Singer Rihanna performs at the Staples Center on June 28, 2011 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

Facebook CEO Mark Zuckerberg (L) watches a demonstration of the new Facebook video chat during a news conference at Facebook headquarters July 6, 2011 in Palo Alto, California. Zuckerberg announced new features that are coming to Facebook including video chat and a group chat feature. (Photo by Justin Sullivan/Getty Images)

A model walks the runway at the Dolores Cortes swim show during Mercedes-Benz Fashion Week Swim 2012 at The Raleigh on July 16, 2011 in Miami Beach, Florida. (Photo by Frazer Harrison/Getty Images for Dolores Cortes)

People play Taiji on a square on August 08, 2011 in Luoyang, Henan Province of China. People all over China mark National Fitness Day on Monday in their own ways. (Photo by ChinaFotoPress/Getty Images)

Alejandro Simon of Spain prepares to serve during their Preliminary Phase Pool E match against Canada during the VISA FIVB Beach Volleyball International at Horse Guards Parade on August 10, 2011 in London, England. (Photo by Scott Heavey/Getty Images)

Fashion designer Hans M. Bachmayer (L), Susanne Wiebe (2R) and Rosanna Davison (R) attend the Susanne Wiebe Fashion Show on August 12, 2011 in Munich, Germany. (Photo by Johannes Simon/Getty Images)

Jennifer Lopez donates a stage outfit that she wore during an American Idol performance to Hard Rock Cafe’s memorabilia collection at her CD signing to celebrate her new album «LOVE?» held at the Hard Rock Cafe Hollywood on May 3, 2011 in Hollywood, California. (Photo by Michael Caulfield/Getty Images)

A Libyan rebel fires on a government jet as a natural gas facility burns on the frontline on March 9, 2011 near Ras Lanuf, Libya. The rebels pushed back government troops loyal to Libyan leader Muammar Gaddafi towards Ben Jawat.