Of course you are entitled to privacy. If you want privacy, live entirely off the grid. If you want to use the infrastructure that was mostly paid for by the government, then you give up that privacy when using that infrastructure.
Now let's not go justifying such invasions by calling them a price to be paid. I realize this is most probably just a cynical remark, but I need to reply nonetheless.
No matter the actual value of "keeping peace" and law + order, it's cost must never go beyond what they represent. Is it lawful for me to keep you under surveillance? Why should it be any different for any government or any authority?
On the other hand, the real enemy is giving real value to anything other than progress. We are artificially creating layers of society based on pieces of paper with pretty pictures on it. How did we get it so wrong? People do not need money. It is not an incentive, it is a blackmail. Every last one of us has done at least one productive thing at one point in our lives, completely free in every conceivable way. And we did it because we felt it was important, right, or simply because we liked it.
I would gladly spend my days contributing as a service tech in a science lab, for instance, or even as an astrophysics researcher (I actually study astrophysics...), without ever wanting any compensation. All I would want is my basic needs fulfilled (water, food, shelter, entertainment) and I would never want or need to feel above or below any other human being on this planet. We can all be equally important.
This is why they watch and try to control us.
They will not relinquish
their high ground of power easily anytime soon. The need to shape the world, or at least a small part of it, is an extension of the need for continued and meaningful existence.
I just wish everyone found a better way to do it. Like programming or space exploration. Or cooking or performing in a circus, just because they like it and they're good at it.