Demonstrators carrying Palestinian flags participate in a joint protest held by several groups in Pittsburgh, Friday Sept. 25, 2009. World leaders are in Pittsburgh for the G-20 summit.
A group of demonstrators hula hoop in protest of the G-20 Summit at the University of Pittsburgh, Friday, Sept. 25, 2009, where world leaders have gathered.
A demonstrator hula hoops while holding a placard during a protest against the G-20 summit near the University of Pittsburgh in Pittsburgh, where world leaders are gathered for the summit.
Demonstrators march with a banner during a march in Pittsburgh, Thursday, Sept. 24, 2009, in protest of the G-20, which is expected to begin in Pittsburgh on Thursday.
Stephon Boatwright of Syracuse, N.Y., wears a Guy Fawkes mask as he participates in a demonstration in Pittsburgh, Thursday Sept. 24, 2009, ahead of the two-day G-20 summit.
Oxfam International activists, including one posing as President Barack Obama, stage a mock football game in Pittsburgh Steelers colors to draw attention to global poverty issues in Pittsburgh, Thursday, Sept. 24, 2009. World leaders are expected in Pittsburgh Thursday for the start of the two-day G-20 summit.
Demonstrators march in the Lawrenceville section in Pittsburgh, Thursday Sept. 24, 2009 in protest of the G20 summit, expected to begin Thursday in Pittsburgh.
Demonstrators march in the Lawrenceville section in Pittsburgh, Thursday, Sept. 24, 2009, in protest of the G-20 summit.
Protesters chant in Arsenal Park in Pittsburgh while organizing a march against the G-20 summit, Thursday, Sept. 24, 2009.
Pittsburgh police in riot gear redeploy after confrontations with protestors near the Strip District in Pittsburgh, Thursday, Sept. 24, 2009. Hundreds of demonstrators marched in protest of the G-20.
A protester throws an object at a police car in Pittsburgh, Thursday, Sept. 24, 2009, while protesting the G-20 summit.
A police officer warns protestors as he holds the pin on a canister in Pittsburgh, Thursday, Sept. 24, 2009.
A protester washes the eyes of a fellow protester during a demonstration in Pittsburgh, Thursday, Sept. 24, 2009. Police fired canisters of pepper spray and smoke at marchers protesting the G-20 summit Thursday after anarchists responded to calls to disperse by rolling trash bins and throwing rocks.
A protester is detained in Pittsburgh, Thursday, Sept. 24, 2009, before the G-20 summit.
Monks from the International Burmese Monks Organization march along Liberty Avenue in downtown Pittsburgh, Thursday, Sept. 24, 2009 to commemorate the Saffron Revolution in Myanmar two years ago.
Members of the environmental group Greenpeace hang from the side of the West End Bridge over the Ohio River with a banner in Pittsburgh, Wednesday, Sept. 23, 2009.
Members of the environmental group Greenpeace are arrested after they hung a banner from the side of the West End Bridge over the Ohio River in Pittsburgh, Wednesday, Sept. 23, 2009.
Lisa Fithian, center, with Three Rivers Climate Convergence, marches with other members of her group down the streets of downtown Pittsburgh, Wednesday, Sept. 23, 2009.
Members of the groups Three Rivers Climate Convergence and the Pagan Cluster march down the streets of downtown Pittsburgh, Wednesday, Sept. 23, 2009.
Protesters make their way through downtown Pittsburgh, on Wednesday, Sept. 23, 2009. The two-day G-20 Summit is scheduled to start Thursday in Pittsburgh.