Actual Facebook Graph Searches is a brilliant blog collecting creepy uses of Facebook's new social graph search. Facebook's product is controversial and I'm glad they launched it. It's fascinating data. Facebook's entire business since day one has been about taking semi-private data and making it semi-public. They blur privacy lines all the time. And they keep abusing their users in all sorts of terrible ways, proactively changing the rules (like the Beacon fiasco). But it doesn't matter, there are still hundreds of millions of people using Facebook every day. Elite nerds complain and wring our hands and have no impact; Facebook just lurches on. They are shifting the definition of privacy.
Our society fundamentally doesn't understand how to treat privacy in the age of databases. From reverse phone books to gun permit maps to scraped lists of political donors, we are continuously astonished when semi-public data seems creepy and privacy invading when aggregated.
So now we have Graph Search, a whole new way of looking at semi-private data that is public and can be creepy when remixed. It's either going to fail fantastically or it's going to be something great and useful. I don't know which. But I'm glad to watch the experiment.
Adapted from my comment in a Metafilter discussion.