New York Police Department tactical police officers stand guard near the New York Stock Exchange on September 9, 2011 in New York City. Officials are stepping up security in New York and Washington D.C. a day after U.S. officials received a credible but unconfirmed terror threat to utilize car bombs on bridges or tunnels in New York or Washington. (Photo by Justin Sullivan/Getty Images)
A protester uses his laptop computer in the “Occupy LSX” camp outside St. Paul's Cathedral ahead of a demonstration against higher tuition fees and privatisation in universities on November 9, 2011 in London, England. Around 4000 police officers are on duty and are to be allowed to deploy baton rounds if needed. The march is expected to finish at London Wall in the heart of the capital's financial district. (Photo by Oli Scarff/Getty Images)
A UCLA student is arrested by Los Angeles Police Department officers after she attempted to escape after eleven student protesters sat in circle in middle of the Westwood and Wilshire boulevard intersection as part of a protest of bank practices and rising fees at public universities on November 9, 2011 in Los Angeles, California. The protest organized by ReFund California was one of several planned at universities around the state. (Photo by Kevork Djansezian/Getty Images)