Twitter has begun restricting who can see its user data, particularly third party firms who publish statistics on how big the Twitter user base is.
The social network, which saw its stock price fall earlier in the year after investors discovered that the growth of monthly active users (MAUs) was slowing, has tried to reverse a recent downturn in fortunes.
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CEO Dick Costolo has instigated an overhaul of the Twitter user interface to increase engagement and replaced the previous COO with a product chief from Google.
Since then, the company's stock price has risen, with some analysts predicting it will reach $60 a share.
Third party companies that publish their own estimations of the Twitter user base often conflict with the site's official figures. Costolo, for example praised the site's 255 million MAUs, while at the same time, Business Insider (opens in new tab) revealed that this figure was just a fraction of the 1 billion users that had tried Twitter.
Third party firms have often reinforced the idea that most users who sign up to Twitter abandon it and most do not actually tweet themselves.
Now these companies have been shut out from Twitter's application programming interface (API), the data source that software development firms use to build helpful products for the site and its users.
Read more: Twitter users start moving to Facebook-esque profiles (opens in new tab)
The reason for the shut out has not been disclosed, but there may be some financial justification for the development. Twitter is building a data business of its own, that looks likely to bring in $100 million in revenue this year, meaning developers who give this information away for free are eating into the company's profits.