This implies that all electronic communications are insecure.
While I like odd scenarios, this would be completely impossible to enforce, for one specific reason.
Anything can be a writing implement, it is simply not possible to ban writing as a concept.
You would need to ban litteracy to do that, and that would quickly ruin any country stupid enough to implement a rule like that.
I can absolutely see banning the printing press, xerox machine, and even a normal printer as they all quickly amplifies the message at a low cost, but normal pen/paper has too many uses and are too easy to make to effectivly ban.