the strongest words were from Google's CEO:
I think judgment matters. If you have something that you don't want anyone to know, maybe you shouldn't be doing it in the first place.Eric Schmidt, quoted by Gawker
"why care about privacy? if you're not doing anything wrong, you have nothing to hide!" it's a cliché older than McCarthyism, but it's a fair question, and none of the answers I've seen have been convincing.
most arguments for privacy that I've read simplify to "privacy is important… because it is!" or "because I like having it!" Even Bruce Schneier's response boils down to little more than a slippery slope argument akin to "if gays get married, pedophilia will flourish!"1.
it's not that simple
now, Schmidt doesn't really believe that privacy should be abandoned. he's looking at information from a security perspective which says that sharing information with someone you don't completely trust makes it public knowledge.
but the real world is more complicated than that. let's categorize real world secrets into two buckets. there are the ones that only you know, and the ones that you share with discretion. your passwords, garage door opener's code, and bank PIN (should) all fall in the former category—these are secrets as defined by the security world.
the latter class of information is where privacy becomes difficult to defend. I enjoy my privacy, but I have to wonder: why don't I want other people knowing everything about me?
let's explore this problem with questions.
why wouldn't you want your boss to know about the party last weekend?
because maybe I'd get fired. hopefully your boss trusts that you don't let your personal life affect your professional life2, but we're on the right track. let's make these situations a little bigger.
why wouldn't you want some armed drunk rednecks thinking you're gay?
because we have hate crime laws, and they didn't get there by accident.
why wouldn't you want people to think you're jewish while visiting Palestine?
because you'd get shot! you know what, just don't visit Palestine. or Israel.
the first question people asked Milami in Texas was usually "what church do you go to?"
and you can bet she was not invited to dinner if she replied "I'm an atheist".
these examples are the reasons we have things like non-discrimination laws—people will treat you as badly as possible if they don't like you. the reason why you should value your privacy is because discretion is what allows you to get along with these people3.
the root cause of these problems is a simple lack of tolerance, and it's not a problem we can solve. we are making improvements—gays can marry in a handful of states, and for the first time in history a president has publicly acknowledged that atheists exist—but there will always be people who will hate you for some reason or another, and privacy is your only tool to mitigate that.
privacy is necessary because without it, we'd never get along.
we shouldn't need it, but we do.
1 in Schneier's defense they're somewhat related, he's just got them backwards—watchdogging necessitates loss of privacy. there is no evidence supporting a link between gays and child molestation.
2 even better, some employers out there have a sense of humour
3 trivia: Linda Lovelace was fired twice from unrelated jobs—not even good ones—due to her role in Deep Throat (source)