Users who have not updated Instagram on their phones still have access to the button that allows for searching your Twitter friends, but the button is now disabled with a message that Twitter has actually cut off Instagram’s access to the API needed to carry out the search. While Instagram is still fully capable of posting to Twitter (which means it still has some access to parts of the API), the app no longer accesses follower or “following” lists.
Why Twitter would do this is unclear. Accessing a friend list does not really reproduce any part of the core Twitter experience, and it is actually the kind of thing Twitter has pushed developers to use the platform for in recent months—as opposed to building new Twitter clients.
It is possible the change is Twitter’s way of taking a shot at Facebook, which recently purchased Instagram, as a competitor in the social network space. The Wall Street Journal reported earlier this year that Twitter even tried to buy Instagram before Facebook. Jealously of Facebook’s purchase seems an unlikely answer, though, especially following Twitter’s recent decision to pull integration from LinkedIn. It rather appears Twitter is finally cracking down on other social networks adopting parts of the Twitter “experience”—an experience Twitter is further monetizing more and more each day.