[caskance]

Any proof would obviously be classified. But there is a lot of circumstantial evidence.

1. He made the statement in the OP. That implies that normal people using modern encryption does not impose a significant barrier to the NSA doing their jobs. Contrast with the 90s when the NSA pushed for the clipper chip, presumably because they couldn't eavesdrop effectively otherwise.

2. The NSA uses its own secret suite A algorithms for things they really care about keeping secret, not the suite B algorithms like AES that they recommend for the rest of us through NIST.

[deelowe]

I'm sorry if this comes across as rude, but that all sounds entirely speculative.

[caskance]

Hopefully it sounds like exactly what I said it was in the first sentence. The only part I could reasonably see as being called "speculative" is the second sentence of the first item, which is clearly marked as an inference.