"Police Secretly Took Over a Global Phone Network for Organized Crime"

Vice:

Encrochat's phones are essentially modified Android devices, with some models using the "BQ Aquaris X2," an Android handset released in 2018 by a Spanish electronics company, according to the leaked documents. Encrochat took the base unit, installed its own encrypted messaging programs which route messages through the firm's own servers, and even physically removed the GPS, camera, and microphone functionality from the phone. Encrochat's phones also had a feature that would quickly wipe the device if the user entered a PIN, and ran two operating systems side-by-side. If a user wanted the device to appear innocuous, they booted into normal Android. If they wanted to return to their sensitive chats, they switched over to the Encrochat system. The company sold the phones on a subscription based model, costing thousands of dollars a year per device.

...

The industry is highly competitive, with companies constantly spreading rumours about the security of each others' devices and uploading YouTube videos to discredit their rivals. Encrochat previously blocked web domains used by other firms' devices, essentially segmenting their customer base from everyone else. That means dealers often need the same sort of phone as everyone else they're working with, unless they want to be locked out of important conversations.