In closing up shop, Twitter has jammed Tumblr’s fingers in the door.

Twitter is clamping down on how other services use its data, as it looks to gain more control over its ecosystem. One of the side effects of that is that useful features, like finding which of your Twitter friends are on another service, are being killed off.

Following in the footsteps of a similar move with Instagram, Twitter has closed the well for Tumblr. Members of the blogging community can no longer connect their Twitter accounts to see which of their followers and followees are on Tumblr.

The removal of Twitter from the “Find friends you know” feature was spotted by BuzzFeed’s Matt Buchanan after he’d written a story questioning whether Tumblr was next up after Instagram on Twitter’s hit list.

It appears the decision was Twitter’s, according to a statement Tumblr gave to the Daily Dot:

To our dismay, Twitter has restricted our users’ ability to “Find Twitter Friends” on Tumblr. Given our history of embracing their platform, this is especially upsetting. Our syndication feature is responsible for hundreds of millions of tweets, and we eagerly enabled Twitter Cards across 70 million blogs and 30 billion posts as one of Twitter’s first partners. While we’re delighted by the response to our integrations with Facebook and Gmail, we are truly disappointed by Twitter’s decision.

Twitter told The Next Web it had nothing to add to the statement it made when it shut off Instagram’s access for a similar feature. “"We understand that there's great value associated with Twitter's follow graph data,” Twitter said at the time, “and we can confirm that it is no longer available within Instagram."

While it may make sense for Twitter to shut off third-party access to its social graph (that is, being able to see connections between people on Twitter), the move may actually do more harm than good.

Much of the activity on Tumblr feeds back into Twitter, as people tweet links to their Tumblr posts. However, it may very well be the case that Tumblr users reblog their friends and tweet about it less often if they’re unable to find them in that community.

One Tumblr user called Twitter’s move “concerning,” while another said: “This is why Twitter sucks.”

“As far as I’m concerned — as an individual user — I’m still taking more value from Twitter than I’m adding to it,” wrote Tumblr user Ian Hines. “As long as that remains the case, I see no reason to cut off my nose to spite my face.”

Photo by derriel street photography/Flickr