International organized crime and drug trafficking groups were dealt a blow by the takedown of an encrypted communication service they used to plan and commit their crimes, the FBI and its international partners announced yesterday.

Canada-based Phantom Secure was a criminal enterprise that provided secure communications to high-level drug traffickers and other criminal organization leaders. The group purchased smartphones, removed all of the typical functionality—calling, texting, Internet, and GPS—and installed an encrypted e-mail system, so the phones could only communicate with each other. If a customer was arrested, Phantom Secure destroyed the data on that phone, which is obstruction of justice under U.S. law. In an attempt to thwart law enforcement efforts, the company required new customers to have a reference from an existing user.

Given the limited functionality of the phones and the fact that they only operate within a closed network of criminals, all of Phantom Secure’s customers are believed to be involved in serious criminal activity. Most of Phantom Secure’s 10,000 to 20,000 users are the top-level leaders of nefarious transnational criminal organizations in the U.S. and several other countries, and the products were marketed as impervious to decryption or wiretapping.