Topic: online vigilantes

One of the blast sites on Boylston Street near the finish line of the 2013 Boston Marathon is investigated and guarded by police in the wake of two blasts in Boston Monday, April 15, 2013. (AP Photo/Elise Amendola) (Elise Amendola)

Reddit's agony

Andrew Leonard
This image from a Federal Bureau of Investigation and Department of Homeland Security joint bulletin issued to law enforcement and obtained by The Associated Press, shows the remains of a black backpack that the FBI says contained one of the bombs that exploded during the Boston Marathon. (AP/FBI)

Our online vigilante future

Andrew Leonard