This is just the beginning. Facebook and Spotify set a nice precedent there to make it en-vogue to just provide a Facebook login for services in the future.<p>For whoever builds the service, it's (marginally) easier to just use FB as an authentication provider and they even get to spin it as "with us, you don't need to store the 1000st password - you can just use Facebook".<p>For Facebook, of course, it's great too as it is one more thing to force people to stay logged in, which in turn is much better data for them.<p>The end users probably wouldn't care either as they are mostly logged into Facebook anyways and if not, it's easy for them to just log in.<p>The only losers are us professionals who know about the implications of such a move and who care about the loss of privacy.<p>And of course the people who had their facebook account suspended for either legitimate reasons or just some oversensitive SPAM protection algorithm. These people are now locked out of their, possibly even paid, account, unable to access it (and remove credit card info). Of course these will be the minority and people won't care.<p>Until it's them that are affected.<p>I can understand that in this day and age you want to provide the users with an option to authenticate with something else than yet another username and password. Google, Twitter, Yahoo or even any OpenID provider (maybe your own). Sure.<p>But just Facebook? This is trouble waiting to happen.<p>I'm saying this as somebody who can't have Spotify anyways due to the complete brokenness of the licensing market, but this still concerns me as it's just another precedent and I'm just waiting for another service I love to force me to use Facebook.