Sister of murdered officer sues Facebook for radicalizing attackers

The sister of a security officer who was murdered in Oakland in 2020 is suing Facebook, alleging that the tech company played a part in radicalizing the two men accused of killing him.

David Patrick Underwood was fatally shot and his partner was wounded while guarding a federal building on 29 May 2020, when a large demonstration over the police killing of George Floyd was underway nearby.

The lawsuit alleges that Facebook used algorithms to steer users to extremist groups as a way to keep them active on the platform, which in turn drives advertising sales and revenue.

Federal prosecutors have said Steven Carrillo, an Air Force sergeant, met his accomplice Robert Alvin Justus Jr through a Facebook boogaloo group, where they agreed to take advantage of the racial justice protests to attack law enforcement officers. Messages obtained by investigators show the men agreed to meet in person and drive to the Oakland protest, where prosecutors said Carrillo fired at Underwood and his partner with a homemade assault rifle before fleeing.

The Guardian reported in 2021 that researchers monitoring online extremism had feared an attack like the one that killed Underwood, after they identified boogaloo groups on Facebook with thousands of members. These groups were used to recruit new members, sharing advice for making weapons and post memes about killing police and federal officials. Facebook said at the time that it took action against hundreds of individual posts that violated its policies against inciting violence but did not ban the boogaloo movement from its platform.