The Zappo's security breach of a couple weeks ago was a reminder that your online passwords, data and activity are vulnerable... and to change your passwords often!
For me, it was a reminder of another sort and crystallized my latest thinking around Facebook & its role on the web. Facebook is obviously a social network. But it has become something different over time... something arguably more important: it is an identity network. Facebook is the identity thread that connects people, content, data, logins, etc. Whether your Facebook social activity has increased or decreased over time - I guarantee your 'social exhaust' has increased. By that I mean: you may post to your Facebook feed regularly - but you are likely using Facebook to access, use and improve the rest of the web.
So how does this relate to Zappos' security breach? Simple: much of this would be avoided if my account was fully tied to Facebook. No new passwords would be exchanged / needed. Changing my single password (and having a long, unique password) would be so much easier if it were just my Facebook account.
For Zappos, this doesn't mean that they are ceding control of their users - they can still supplement accounts & details. Rather, it means outsourcing identity to Facebook... and that has some big benefits.