Just spotted the PS to the above:

PS: A small bipartisan group of Congressfolk, including Senator Ron Wyden (D-OR), has urged the UK not to, for the purposes of surveillance, force Apple to disable the end-to-end encryption of certain iCloud data stored at rest. This follows earlier political pressure from the group to change the minds of the British government.

.... never mind that decrypting the data at rest is actually impossible, unless the encryption has already been sabotaged.