It's a losing battle, unfortunately. We can't remember one simple 2048-bit private key, we emit all varieties of radiation, we leave a literal trail of identifiable chemical signatures, we're susceptible to an enormous variety of attacks, have only a vague notion of what's going on around us (or, for that matter, inside us), have predictable needs and habits, share important details of our lives with others, and last but not least, are frequently willing to trade our privacy for a little convenience or money.
In short: we're loud and messy, and trying to make a human invisible to the technology of today and tomorrow is ultimately futile. It's like DRM; the most you can do is make it slightly harder and impose laws declaring the water should stay in the sieve.
Hopefully we'll wise up someday and stop caring about the pointless minutiae of each others' lives, and decide that as long as technological advance means we're heading for a panopticon anyway, it needs to be owned by all the people.
Not holding my breath, though.