And of course, it just won't work
Lacking time to peruse all comments so I'm no doubt repeating what others have already pointed out: the very people you want to surveil will encrypt their data before slipping it on to the phone that's being used to transmit it. Given you're a technical audience I needn't even bother specifying the many ways this could be done because it's obvious, simple and effective.
Just one off the cuff: The outstanding resolution of phone cameras and displays suggests one immediate and easy route. One device, unconnected to any network of any kind, encrypts your message and displays it as an image. Your connected phone takes a picture of the other's screen. Steganography to obfuscate is an option, of course, and I'd guess you could easily use this method for messages of a few hundred characters at least.
The stubborn ignorance and stupidity of politicians never fails to exceed plausibility.
Biting the hand that feeds IT
