the question really isn't about privacy, but rather about freedom. Not the freedom as is touted but rather freedom from consequences of no-privacy.
repercussions of free speech without the protection of anonymity would be one. Just look at any whistle blower in recent history. That is at a governmental scale. However just think about having your private words, pictures, correspondence in public domain with the narrow minded social infrastructure that current US society displays in its fervor...
Make a provocative comment and be censured from work, friends and future prospects...
I am willing to buy the argument, if you are not guilty you shouldn't have anything to hide when the society is at a socially elevated level to accept people as they are without judgement... and no I won't hold my breath for that to happen.