The Minneapolis Police Department's website has shown signs of a cyber-attack since late Saturday, days after a video purported to be from the hacktivist group Anonymous promised retribution for the death of George Floyd during an arrest.
Websites for the police department and the city of Minneapolis were temporarily inaccessible on Saturday as protesters in cities around the U.S. marched against police violence aimed at black Americans.
By Sunday morning, the pages sometimes required visitors to submit "captchas" to verify they weren't bots, a tool used to mitigate hacks that attempt to overwhelm pages with automated requests until they stop responding.
Officials with the police department and the city didn't immediately respond to requests for comment.
Anonymous posted a video on their unconfirmed Facebook page on May 28 directed at the Minneapolis police. The post accused them of having a "horrific track record of violence and corruption."
The speaker, wearing a hoodie and the Guy Fawkes mask that's a well-known symbol of the group, concludes the video with, "we do not trust your corrupt organization to carry out justice, so we will be exposing your many crimes to the world. We are a legion. Expect us."
The video was viewed about 2.7 million times on Facebook, during a weekend in which violence swept the U.S. as protesters clashed with law enforcement and National Guard troops.
While many demonstrations have been peaceful, others have devolved into rioting. Several cities issued curfews and police have at times turned their rubber bullets and mace on the activists and on journalists covering the protests.
President Donald Trump on Sunday cast blame on the media for stoking the violence that's followed the death of Floyd, an unarmed black man, in Minnesota police custody.
Anonymous began appearing as a loose collective of hacktivists around 2003, emerging from message boards like 4chan, and launching attacks against organizations from the Church of Scientology to the Federal Bureau of Investigation and the terrorist group ISIS. Among their other targets were Mastercard Inc., white supremacists and members of the Ku Klux Klan.
During the Arab Spring in 2011, its hackers took down government websites in Tunisia and Egypt and would go on to infiltrate government websites with distributed denial of service attacks in Malaysia, India, Syria, China and Nigeria.
A 2012 cyber attack on PayPal in retaliation for shutting off service to Julian Assange's Wikileaks cost the company millions.
In 2014, Anonymous attacked Ferguson City Hall's website after Michael Brown was shot and killed, prompting riots throughout the city. The group threatened the St. Louis County police chief with the public release of his personal family information if he didn't release the name of the police officer who shot Brown. A member of the group initially misidentified the officer. The group then went on to threaten police and the local government with cyber-attacks if protesters were abused or harassed.
In the years since several of its members have been arrested and charged with computer crimes and hacking attacks. Among them was Deric Lostutter, who in 2017 was sentenced to two years in federal prison for hacking a high school football team's website in connection with a 2012 rape case.
Last November, James Robinson was sentenced to six years in prison for distributed denial of service attacks on police and local government in Akron, Ohio in 2017.