Berlin Wall 1989
A man hammering at the Berlin Wall, as the border barrier between East and West Germany was torn down after 28 years. on Nov. 12, 1989. (John Gaps III, AP) Boston.com

Construction worker holds up a sign in solidarity with protesters
Photo by Spencer Platt/Getty Images Huffington Post

Wikileaks founder Julian Assange

Cleaning up the park

"We Will Not Be Silent"

NYPD Officer Runs Over Observer

NYPD Arrests Legal Aid Observer

Zuccotti Park
 Huffington Post

Occupy Boston
AP Photo/Josh Reynolds Huffington Post

Day 9 Occupy Wall Street
 Huffington Post

Trade Unions Join "Occupy Wall Street"
STAN HONDA/AFP/Getty Images Huffington Post

WTO protests in Seattle November 30 1999
Pepper spray is applied to the crowd. Wikipedia

Seattle WTO Protest

Seattle Police officer fires his weapon at demonstrators
Photo by Paul Joseph Brown Seattle Post Intelligencer

Protestor hit by tear gas and pepper spray
Photo by Paul Joseph Brown Seattle Post-Intelligencer

Protestor Arrested
Photo by Mike Urban Seattle Post-Intelligencer

Long Range Acoustic Device
Marvin Fong, The Plain Dealer The Plain Dealer

Birmingham police use dogs
Charles Moore, Black Star The Plain Dealer

Oakland Police Fire on Protestors
 Associated Press

Protestor Injured by Police at Occupy Oakland
 Associated Press

Occupy Portland Pepper Spray
Photo by Randy L. Rasmussen/The Oregonian The Oregonian

Occupy Oakland
A group of police officers from various law enforcement agencies arrest an Occupy Oakland demonstrator near Frank H. Ogawa Plaza during a day-long protest in Oakland, California January 28, 2012. REUTERS/Stephen Lam Associated Press

Occupy Oakland
Police used teargas to drive back protesters following an attempt by the Occupy supporters to shut down the city of Oakland. (Noah Berger/AP)

Environmental Campaigner
An environmental campaigner protesting against GM crops. A study said it can cause organ damage.

84 Year Old Pepper Sprayed by Seattle PD
84-year-old Dorli Rainey was pepper sprayed during a peaceful march in Seattle, Washington. She would have been thrown to the ground and trampled, but luckily a fellow protester and Iraq vet was there to save her. (Joshua Trujillo/seattlepi.com) Seattle Post-Intelligencer

Oakland Police Critically Injure Iraq War Vet During Occupy March October 25, 2011
Oakland Veteran shot with police projectile is in critical condition.

Kent State, May 4, 1970: America Kills Its Children
Victims: Allison Krause, Jeffrey Miller, Sandra Scheuer and William Knox Schroeder.

Occupy Wall Street
Demonstrators with 'Occupy Wall Street' sweep the streets clean near Zuccotti Park in New York. Protesters have no toilet facilities of their own and depend on local restaurants including McDonalds. There have also been reports of locals complaining about demonstrators urinating and defecating in the streets. (AFP Photo/Timothy A. Clary)