In the past week, Facebook has prevented multiple services from using its Social Graph. It wants to keep its most precious data—knowing who people's true friends are—out of competitor's hands. Other companies often implement Facebook's "Find Friends" feature into their signup processes. Products are more enjoyable to use when people you know are using them too. Twitter used to use Find Friends to suggest people to follow. Path uses it to show which of your friends are already on the service.facebook at schoolfacebook proxy But apparently Facebook has had enough. It's utilizing a line in its platform policy that states, "Competing social networks: (a) You may not use Facebook Platform to export user data into a competing social network without our permission.” Graph Search is a privacy-aware search, Zuckerberg said. That means that it only searches content which has been shared with you and that your search results will differ from the search results someone else will see ... even if you enter the same exact queries.facebook at schoolunblock facebook In the past few days, Facebook has prevented a voice-messaging app, Voxer, from utilizing Find Friends. It also blocked Twitter's new animated-GIF-style video app, Vine, from using its data. Most recently, Facebook cut off a new social search app released by Yandex called Wonder just three hours after it launched. Yandex begged for its life; Facebook didn't care. Facebook told TechCrunch it cuts off companies who are either competitors, or who contribute little back to Facebook.facebook at schoolaccess facebook Is it smart for Facebook to hoard its social data? It depends how strict Facebook becomes. It could prevent competitors from using Facebook to their advantage, but it could also deter startups from building on its platform. A lot of new companies require Facebook's data and Find Friends feature to make their products worth while to early users.