Boston Phoenix has a fascinating story up about the unusually tech-centric hunt for Craigslist Killer. In the course of reporting, the paper's reporters came across something they, and the general public, had never seen before: The full results of a Facebook subpoena.
This is what Facebook sends to the police when they (or rather, a judge) asks nicely enough (view the entire file here):
When you click on someone's profile, it's logged. Other Facebook users don't know you're looking at their profiles, but Facebook itself most assuredly does. Or rathercan, if the police come asking.
This is far from the first subpoena Facebook has cooperated with, just the first we've been able to look at. Here's what the site says about its policies for cooperating with law enforcement:
We work with law enforcement where appropriate and to the extent required by law to ensure the safety of the people who use Facebook. We may disclose information pursuant to subpoenas, court orders, or other requests (including criminal and civil matters) if we have a good faith belief that the response is required by law. This may include respecting requests from jurisdictions outside of the United States where we have a good faith belief that the response is required by law under the local laws in that jurisdiction, apply to users from that jurisdiction, and are consistent with generally accepted international standards.