More than 800 suspected criminals have been arrested worldwide after being tricked into using an FBI-run encrypted messaging app.
The operation, jointly conceived by Australia and the FBI, saw devices with the ANOM app secretly distributed among criminals, allowing police to monitor their chats about drug smuggling, money laundering and even murder plots.
Officials called it a watershed moment.
Targets included drug gangs and people with links to the mafia.
Drugs, weapons, luxury vehicles and cash were also seized in the operation, which was conducted across more than a dozen countries. This included eight tons of cocaine, 250 guns and more than $48m (£34m) in various worldwide currencies and cryptocurrencies.
Australian Prime Minister Scott Morrison said the operation had “struck a heavy blow against organised crime” around the world.
European Union police agency Europol described Operation Trojan Shield/Greenlight as the “biggest ever law enforcement operation against encrypted communication”.
The FBI began operating its own encrypted device company called ANOM, and covertly distributed devices with the chat app among the criminal underworld via informants.
The idea for the operation came after two other encrypted platforms were taken down by law enforcement agencies, leaving criminal gangs in the market for new secure phones.
The devices were initially used by alleged senior crime figures, giving other criminals the confidence to use the platform.
“You had to know a criminal to get hold of one of these customised phones. The phones couldn’t ring or email. You could only communicate with someone on the same platform,” the Australian police explained.