NB Privacy vs Secrecy
I'm concerned there might be some clever officialese word games going on here - at one end is the simplest privacy is where something is marked as 'private' and people have the manners not to look, and the other is 'secret' which is in theory properly encrypted to deliberately prevent anyone from looking.
Privacy legislation/regulations seem to live somewhere towards the 'basic privacy' end of the scale, i.e. not collecting information in the first place, and using basic masking or encryption for a 'conversation', and as with email, normally encrypted only during transmission (and even then only about 10% of it) and not whilst in the queue/mailbox. The 'manners' bit is the authorities not demanding access but then again this has an actual paper trail and someone to take the blame (in theory, probably tricky in practice).
The Secrecy end of the scale, the one the guvmint don't like, is where they get a court order and demand your encryption key and see everything you said anyway, even though they couldn't listen in at the time. That said, they actually have to justify it to someone outside their own circle.
Privacy for not collecting data in the first place, and session secrecy to stop people listening in, and something decently clear when someone official wants to ask if I bought anything other than an Automatic Video Recorder.