There is a point being totally missed in this thread and that is the UK government basically ignore all security common sense and do absolutely incomprehensible things like discuss national security over WhatsApp and Zoom, as a British citizen, in my eyes this absolutely amounts to treason as they're knowingly potentially giving away state secrets, anyone else would be instantly jailed.
UK government and any departments discussing sensitive matters (or everyone, really) should not be using a) off the shelf phones, and b) should not be using public communications networks full stop, nevermind foreign communication platforms.
UK government and any departments discussing sensitive matters (or everyone, really) should not be using a) off the shelf phones, and b) should not be using public communications networks full stop, nevermind foreign communication platforms.