I remember once hearing that a privacy advocate had replied to that argument from a politician with "Senator, when you make love to your wife, do you kiss her breasts?"
The fundamental right to privacy is actually based on the right to personal safety, or the right to protect yourself from the mob. In any particular context, an individual may well have the need to hide something. For example, one might happen to be gay and alone on a bus with 7 violent homophobes. This is an extreme case, but history is rife with examples where even the "society at large" context was manifestly unjust. (Our own towards homosexuals, for example. Last night, I was hired as a musician for a Baptist singles ministry group. I thought it was prudent that I kept conversation away from certain topics.)
Saying that there's no right to privacy implies that all contexts are benevolent and just. But we know that the world is not always just, so there must be a right to privacy.
If everyone could find out such knowledge about everyone else on a whim, would people stop being so paranoid about the question, and all others like it?
I see privacy as just a way to protect oneself in light of an unequal balance of informational power. If this imbalance were corrected--if everyone instantly knew everything and anything they wanted to know--a form of mutually-assured destruction would ensure continued politeness, or as the author put it, "dignity and respect." We would simply stop caring about such things--gossip is a non-issue when everyone (metaphorically, mind) lives together naked in a brightly-lit room, and speaks in sweeping motions and loud voices.
In a privacy-less world, the senator would simply reply "yes" or "no," but the question wouldn't have been asked in the first place, as it wouldn't be especially inflammatory--anyone could know all they wanted about anyone else's sexual habits, and so it wouldn't be at all interesting, or even at all intimate (once the novelty wore off, of course.)
