The FBI already has some information -- that they got from NSA -- that they desperately want to use.
But they can't use it yet because they lack a credible cover story to use for "parallel construction" (look it up).
They tried to use Apple to get their little parallel construction cover story -- and now they're just changing the rules so they don't even have to use parallel construction any more.
During the big Snowden leak time frame, it came out that the DEA had been conspiring with other agencies, using the NSA data, to perform parallel construction illegally.
So we already know it's going on within the US Government. Is the FBI using it? Whatever the line is between plausible and damn certain, that's perhaps where this falls.
But they can't use it yet because they lack a credible cover story to use for "parallel construction" (look it up).
They tried to use Apple to get their little parallel construction cover story -- and now they're just changing the rules so they don't even have to use parallel construction any more.
Interesting times.