Facebook helped the FBI bring down an international criminal enterprise that infected nearly 11 million computers with malicious software, accounting for more than $850 million in losses.
Reuters reports the social networking site helped identify the responsible parties and provide security systems for detecting infected accounts.
Facebook also provided tools for removing the threats, Edwin Chan writes.
The bureau arrested 10 people who used the Yahos software, known as a butterfly botnet, to target users between 2010 and October 2012.
The accused come from Bosnia and Herzegovina, Croatia, Macedonia, New Zealand, Peru, the U.K. and the U.S., the report said.