Shortly after Twitter announced that it had acquired video sharing app Vine, Facebook began blocking Vine from using its "find people" function to find friends with Facebook accounts.
Turnabout, it seems, is fair play, or perhaps just business as usual. Last July, Twitter blocked Facebook's Instagram app from using its API to find friends with Twitter accounts within Instagram.
Facebook also blocked Russian search engine Yandex's new Wonder app, which provides users with a way to search social data streams. Facebook, as it happens, just introduced its own social search service, Graph Search.
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Yandex confirms that Wonder has been blocked by Facebook. "We are in touch with Facebook to enquire about the reasons for this and what can be done to solve this problem," a Yandex spokesman said in an email. "As of now, any new users trying to sign up to Wonder with their Facebook account receive a notification by Facebook: 'An error occurred. Please try again later.' Those users who have already signed up can still ask questions, but the Facebook data will not be updated. Instagram, Foursquare and Twitter data are updated as normal."
Twitter declined to comment.
On Friday, Facebook published a blog post to clarify its platform policies. The company says that it has expanded its rules to cover apps that "either replicate our functionality or bootstrap their growth in a way that creates little value for people on Facebook, such as not providing users an easy way to share back to Facebook..."
The new rule (I.10) includes a reciprocity requirement. It states, "If you use any Facebook APIs to build personalized or social experiences, you must also enable people to easily share their experiences back with people on Facebook."
The rule also prohibits replicating "a core Facebook product or service without our permission." Presumably, Facebook believes Yandex's Wonder resembles Graph Search.
Companies that provide data through APIs often impose limits on how their APIs can be used to prevent abuse. But it is common for companies to impose API limits for the sake of competitive advantage. Facebook in 2010 reportedly blocked Apple's Ping social network from accessing its data, a move that probably hastened Ping's subsequent demise. Google for years limited developer access to its AdWords API, and only recently agreed to lift its restrictions on automated data export to make peace with the Federal Trade Commission. Microsoft has imposed API limits in Windows RT that prevent third parties from creating interoperable browser software. Mozilla, for example, cannot port its Firefox browser to ARM-based Windows RT without the necessary API access.
And this is not the first time that "core functionality" has been an issue. In 2009, Apple refused to approve Google Voice for iOS because it "[appeared] to alter the iPhone's distinctive user experience by replacing the iPhone's core mobile telephone functionality and Apple user interface with its own user interface for telephone calls, text messaging and voicemail." Facing pressure from regulators, Apple subsequently relented.
A year and a half ago, anti-social behavior from social platforms prompted noted venture investor Fred Wilson to recommend -- in colorful terms -- that companies build their own technology rather than relying on others.
Dalton Caldwell , CEO of App.net, founded his company out of dissatisfaction with the capricious nature of third-party platforms like Facebook and Twitter. In a scathing open letter to Facebook CEO Mark Zuckerberg last summer, he condemned Facebook and Twitter for being willing change the rules affecting developers to chase profit. He argues that successful social platforms will become more like infrastructure companies than media companies. Presumably, this means adopting terms of service that give developers more rights or operating under the sort of regulatory structure that limits utilities.