Anonymous has announced a "Day of Vengeance" on September 24 in retaliation for the execution of Troy Davis as well as arrests during a protest on Wall Street.

To avenge the Wednesday execution of Troy Davis, hacktivist group Anonymous has added the Atlanta Police Department to its list of targets for a nationwide cyber attack scheduled for this Saturday, September 24.

"For the death of Troy Davis TARGET: GA State Parole Board www.pap.state.ga.us DOWN. Expect us Georgia," tweeted Anonymous affiliate, @PLF2012 (People's Liberation Front 2012).

Troy Davis was a Georgia death row inmate executed late Wednesday night despite the appeals of hundreds of thousands of people around the nation who believed he was innocent.

On Wednesday, Anonymous announced a "Day of Vengeance" starting at noon ET this Saturday, when aligned hackers would launch cyberattacks on targets like "Wall Street, corrupt banking institutions, and the New York City Police Department."

Anonymous and other cyber liberation groups will also stage outdoor protests around the world.

What are they avenging? According to Anonymous' press release, during a peaceful outdoor protest held on Wall Street on September 17, heavily armed police officers began arresting protesters for wearing the iconic Guy Fawkes mask, alleging violation of the 1845 "mask" law. On September 20, the last day of the protest, Anonymous said members of the NYPD swooped in to the public space and used "excessive force" to clear the area.

"Anonymous and the other cyber liberation groups around the world together with all the freedom loving people in the USA will NOT stand for this. We will peacefully yet forcefully resist the abuses of the NYC Police Department," it said in a statement posted at Pastebin.

"In coordination with these protests across the USA on September 24th, Anonymous and other cyber liberation groups will launch a series of cyber attacks against various targets including Wall Street, Corrupt Banking Institutions - and the NYC Police Department. We encourage the media to follow the Twitter feed @PLF2012 for ongoing reports throughout the day," the group said.