As someone who tends to be the furthest to the left of most political conversations, I find myself as the proverbial "blacksheep" of the Liberal world on a couple of issues.
And this so called "right to privacy" issue is one of them (along with nuclear power and affirmative action; most lefties hate my stance on those three).
Nowhere in the US Constitution does it use the term "right to privacy." It is hinted at, but not spelled out.
A person's right to privacy begins and ends at their front door. It does not include what you do outside your home (unless its in someone else's home, then their privacy protects you); it does not include what you do with devices that send signals radiating outward (ie mobile phones) that pass through me and everyone else.
Personally, I do not feel that we should wait to get a DNA sample of someone until they get arrested: it should be done at birth, and your DNA sequence should be used throughout your life as a means of proving your identity. Of course, I also think that some sort of patent or copyright should be issued to each individual to prevent biotech companies from using gene sequences that are found in people as part of their scientific research. If corporations can patent gene sequences they create, then each of us should be able to hold the patent on the gene sequence that created us.
Simply put, anyone who thinks that a right to privacy goes beyond what you do within your own home, especially in the Age of Information, is hopelessly naive, as naive as all those who think the Second Amendment is there to protect their right to have any and all sorts of firearms they want to "protect them from gov'ment tyranny."
Just another reason among many that we need a new Constitutional Convention to overhaul and rewrite that archaic, out of date document. And I mean a COMPLETE rewrite.