Under E2EE, decryption keys are stored only on devices, meaning that governments can’t eavesdrop on what is being said by demanding the keys from service providers. Not surprisingly, governments hate this, leading to the suggestion in countries such as the US and UK that the technology might be outlawed at some point.

Ironically, Telegram doesn’t use this technology by default, relying instead on traditional server-side encryption where the service provider holds the keys. The app offers a limited version of E2EE called ‘Secret Chats’ but this can be awkward to set up.

That means that by default Telegram can see what is being said if it wants to but, according to the French charges, has refused to co-operate when asked to release details during police investigations.