This all breaks down to one thing. The government can detain you indefinitely and is equipped to kill you. No private enterprise can do either of these things legally.
The government holds deadly force. Private enterprise is going to do some horrifying things with your data, but barring a cyperpunk dystopia, it lacks the capability to end your life.
What exactly are you wishing for here? That the government be prevented from accessing information on you under all circumstances? To my knowledge, a subpoena is usually pretty reasonable circumstances, and it was subpoenas specifically that we were discussing. If you feel otherwise, I would like to hear more.
Subpoenas are irrelevant when they are siphoning all the data they can get their hands on through programs like PRISM enabled by Patriot act.
And yes, while it doesn't matter what they can and cannot do with your data now (unless you're a criminal not much, obviously), if the government ever becomes excessively authoritarian and dictatorial, keep in mind they can retroactively go through all the data they ever gathered on you and find something to string you up with.
Wait until the day that Google announces that they're opening up their entire database of search histories in the name of transparency. It will be an opt-out initiative where those wishing to keep their data out of the open will have to pay a monthly "processing and maintenance fee" to "manually" remove your entries from the database.
The government holds deadly force. Private enterprise is going to do some horrifying things with your data, but barring a cyperpunk dystopia, it lacks the capability to end your life.