Users want their secrets to be secret.
Apple wants its users' secrets to be secret.
The UK wants the fact it wants Apple to reveal anyone's secrets to be secret.
replies(1):
Apple wants its users' secrets to be secret.
The UK wants the fact it wants Apple to reveal anyone's secrets to be secret.
I think it's worthwhile to point that if you're using "panopticon" in the literal sense (rather than shorthand for "boy that feels too far to me") then any surveillance that relies on 3rd parties [1] and gag orders to avoid making the target aware is, in fact, already the full panopticon scenario.
In that case the bounds on your middle ground make what is between obvious: information is obtained by warrants served directly to one or more participants in the communication.
[1] In the "3rd party doctrine" sense