Privacy advocates talk about "metadata is data" as if the government's lawyers don't understand that bits are just bits. What privacy advocates don't understand is that the "metadata" distinction is about generation, ownership, and control, which are implicated in the 4th amendment by the word "their."
I think the libertarianness of the whole digital privacy movement is losing a lot of potential supporters. If the restrictions on government surveillance were bundled together with restrictions on corporate surveillance with a consumer protection angle, I think you'd get a lot more people on board.
It has plenty of reason to want dissidents in jail which you may care about for various reasons both practical and ideological. Though I think jail is outmoded: with (near) total surveillance there are more effective deterrents.
I do think you are right about the lack of emphasis on corporate surveillance.
Let me quote the Supreme Court decision establishing a right to privacy [1] (which was not previously considered present!): "Secondly, the Fourth Amendment cannot be translated into a general constitutional 'right to privacy.'" That Amendment protects individual privacy against certain kinds of governmental intrusion, but its protections go further, and often have nothing to do with privacy at all."
The decision goes further to note: "But the protection of a person's general right to privacy -- his right to be let alone by other people -- is, like the protection of his property and of his very life, left largely to the law of the individual States".
In other words, one may have statute protection, but not blanket Constitutional protection. And that opens up the possibility of the ones writing the statutes carving out "foreign intelligence" exceptions.
And this is all in accordance with the decision to invent the "reasonable expectation of privacy", it's not even going into later decisions like Smith v. Maryland which tended to expand government search ability.