The Signal Messenger app is displayed on a smartphone in Hong Kong, China.
Roy Liu | Bloomberg | Getty Images
Federal investigators say they accessed encrypted signal messages sent in the lead up to the January 6, 2021 uprising in the U.S. Capitol and used them as evidence to indict the leader of the Oath Keepers, an extreme right-wing militia group. and other defendants in seditious conspiracy.
In a new legal complaint published on Thursday, the Justice Department claims that the defendants conspired to vigorously prevent the transfer of power between then President Donald Trump to Joe Biden, including by attempting to take control of the US Capitol.
The complaint relates to numerous messages sent through Signal, an end-to-end encrypted messaging app. Encryption encrypts messages so that no one can read them but the intended recipients – including the platform hosting the messages.
It’s not clear how investigators got the news. Representatives from Signal, the Department of Justice and the Federal Bureau of Investigation did not immediately respond to CNBC’s requests for comment.
One possibility is that another recipient with access to the messages passed them on to the investigators. The complaint refers to group messages that are running in the app, so it is possible that another participant was involved in these chats.
Encryption has been a point of contention between investigators and tech companies for years. While law enforcement fear that criminals are using encrypted technology to hide wrongdoing, tech companies like Apple have argued that it is an important tool for protecting privacy. Law enforcement agencies have tried in the past to trick tech companies into opening their devices to help investigate serious crimes, but companies like Apple argue that breaking encryption for U.S. investigators puts the entire system at risk and potentially leaves room for foreigners Opponent lets weaknesses be exploited.
The subject became particularly well known in 2015 when Apple refused to crack the encryption of a suspect’s iPhone after a mass shooting in San Bernadino, California. After a tense argument, the investigators finally managed to crack the encryption themselves.
However, some law enforcement agencies have said that newer security features in iPhone software are now making it difficult for them to technically access these devices, even if they can get an arrest warrant.
The problem re-emerged under the Trump administration, including when Meta, then known as Facebook, announced plans to merge all of its messaging services and encrypt them end-to-end. Law enforcement said the plans would hamper their ability to crack down on child sexual abuse material on the platform.
Subscribe to CNBC on YouTube.
WATCH: Why the U.S. Government Is Questioning Your Online Privacy