So privacy is about control...but what if you don't even know what you're controlling?

It's becoming practically a mantra, the way it's being repeated everywhere: privacy is about control.  And a newish location-based social network seems to be taking this to heart.  As ReadWriteWeb describes, Rally Up has settings that allow you to control how information is being disseminated to your "real friends."  Definitely interesting.But then there's the week's big news about the Library of Congress archiving Twitter.  Not surprisingly, some people are nervous.  Even if all the Tweets archived were public Tweets, it's unclear if those people equated the public nature of their Tweets with consent to being archived.  Even those who actively, purposefully, consciously were public in their Tweets may have ended up revealing more information about themselves than they intended.  Reading the pattern of tweets could allow researchers and others to deduce information people didn't know they were broadcasting.  If that seems implausible, keep in mind that the data is valuable precisely because there's information in it that's not immediately obvious.The difficulty with privacy in our age is that embarrassing things, which people have been doing since the dawn of time, are now so easily memorialized and stored for a very, very long time.  Fifteen years ago, you could do something stupid on spring break and at worst, be a laughingstock among your friends and their friends.  Now, a photo of you doing something stupid could stick around and impact your life years later, when a potential employer is checking you out.It's definitely troubling, and not an issue that is resolved only through multiple-choice settings.  On the other hand, maybe we'll all just get used to it once we've been living in that world long enough.  Eventually, the generation that has embarrassing photos on Facebook will grow up and be hiring people themselves.  Maybe they won't care so much when they find a drunken photo of a potential hire.