Facebook's relationship status with Microsoft's Bing has changed to "it's complicated."
Facebook has ditched Microsoft's Bing search engine as a provider, in favor of a proprietary engine.
There had previously been an option to view Bing results during a Facebook search, but over the past few days it has disappeared without notice.
The move to its own engine, based on the much heralded Social Graph, will allow Facebook to focus the results on comments, photographs, and other information from the Facebook ecosystem. In other words, cultivate a walled garden.
Both sides have confirmed the move that was first reported by Reuters on Friday.
A Facebook spokesman said, "We're not currently showing Web search results in Facebook Search because we’re focused on helping people find what's been shared with them on Facebook.
"We continue to have a great partnership with Microsoft in lots of different areas."
Microsoft confirmed that the move happened "a while ago," although the disappearance became apparent only last week.
Facebook chief Mark Zuckerberg said previously that he believes that searching Facebook could one day supersede searching the Web as a whole, noting that the site gets more than a billion search queries a day, comparable to a small search engine.
Microsoft still has a "cozy" relationship with the social network that extends to a small but significant stake. It was also responsible for providing banner ads for the site until 2010 when Facebook took responsibility for advertisement in-house.