You cannot hide what you’re listening to from your friends on Rdio. You cannot have a private pinboard on Pinterest. You cannot hide your favorites on Twitter. You cannot delete titles from your Netflix history. (Netflix isn’t shared on Facebook right now, but it’s not for lack of wanting to.) Spotify freaks out a little bit when the social thing isn’t working and harangues you constantly to connect it to your social networks (even though it, admirably, has a private mode). Washington Post Social Reader shares whatever article you’re reading in real time, unless you dive deep into Facebook’s settings and decide to only share with yourself (which is kind of weird, to think about it that way; there is no not sharing, just sharing by yourself).