Earlier in the day, Facebook said hackers exploited a vulnerability in the social media platform’s code to use the "View As" feature to control accounts.
"The news that at least 50 million Facebook users had their accounts compromised is deeply concerning," Warner said on Friday. "A full investigation should be swiftly conducted and made public so that we can understand more about what happened."
The incident, he added, is also an indication that Congress must take action to protect privacy and security on social media.
