Federal investigators say access to encrypted Signal messages helped them to charge the leader of the Oath Keepers, an extremist far-right militia group, and other defendants in a seditious plot on Jan. 6, 2021.
Encryption scrambles messages for recipients so that no one else — not even the platform itself — can read them.
It's not clear how investigators gained access to the messages, but encryption has been a point of tension between law enforcement and the tech industry for years.