I don't think that's what is being said, mainly? Like that's why Anthropic wants to have it in the contract(s) with the government?

At the same time, it is expressly illegal in some circumstances; that was the whole core of the Snowden revelations. The NSA and CIA are expressly curtailed from doing that by law — there are cases where they may surveil citizens with a court order, but not "mass" surveillance. There are some restrictions on the military along those same lines.

Keywords: Executive Order 12333, FISA, National Security Act, Posse Comitatus Act