This is getting a lot of publicity right now. Spotify is an online service which lets you pay about $10/month to listen to all the music you want on your desktop or mobile device. They recently changed their sign-up policy so that you now need a Facebook account to sign up for a spotify account, and a lot of people are upset.
And more comments here: http://news.ycombinator.com/item?id=3038815
It will be interesting to see if they revert this update since Mr. Zuckerberg seems to endorse Spotify.