Holding signs Chase Stanek and his brothers, Hunter and Wyatt, left to right, await the return of their father, Sgt. 1st Class David Stanek, Dec. 7, 2011, at the Nebraska National Guard Air Base in Lincoln, Neb. About 100 Nebraska Army National Guardsmen and women from the 195th Forward Support Company returned home after serving in Afghanistan. (Corey Perrine/The World-Herald/AP Photo)

Virginia Tech police officers console one another as they move toward the scene where a fellow police officer was killed in a parking lot on the campus of Virginia Tech, Dec. 8, 2011, in Blacksburg, Va. A man killed a police officer and another person after a traffic stop Thursday at the university. (Don Petersen/AP Photo)

Firefighters try to extinguish burning oil tankers allegedly torched by militants at a terminal on the outskirts of Quetta, Pakistan, Dec. 8, 2011. More than 20 tankers were torched in Pakistan carrying fuel for U.S. and NATO troops in neighboring Afghanistan, in the first reported attack since Islamabad closed the border to protest coalition airstrikes that killed 24 Pakistani troops last month. (Arshad Butt/AP Photo)

The moon illuminates the spires of the Duomo gothic cathedral in Milan, Italy, Dec.8. 2011. (Luca Bruno/AP Photo)

A farmer stops traffic in Duisburg, western Germany, to shepherd his flock of 150 geese across the street, Dec. 8, 2011 in Duisburg, Germany. The geese enjoy an outdoor enclosure during the day to feed on fresh grass and move back to their night accommodation in the evening. (Frank Augstein/AP Photo)

Camilla, Duchess of Cornwall, performs a 150 million euro trade under the guidance of Simon Bond, dressed as a wolf, during the ICAP Charity Day, Dec. 7, 2011, in London. The Duchess of Cornwall was supporting Maggie's Cancer Caring Centres of which she is a patron. (Chris Jackson/WPA Pool/Getty Images)

Former New Jersey Gov. and Sen. Jon Corzine testifies before the House Agriculture Committee regarding the bankruptcy of MF Global, on Capitol Hill in Washington, Dec. 8, 2011. (Saul Loeb/AFP/Getty Images)