This is the crux of the issue. Where's the line between email and Facebook? "If you don't want it public, don't put it on the web," they say. But that's way too simplistic. Webmail's on the web, and we (and the law) certainly have different expectations of it. So where's the line? And how evil is it to pull a Facebook-style privacy bait-and-switch? There's a privacy spectrum between email and Twitter, and FB is somewhere in between.

Don't get me wrong -- I haven't taken sides, and can't be arsed to care, having never gotten involved with FB.