Twitter changes provokes anger from developers
Developers and users of Twitter have reacted angrily to changes made by the social network to restrict creation of third-party applications.
Any new app that wants to serve more than 100,000 users must now seek the company's explicit permission.
Apps which already have more than 100,000 users are allowed to double their user base before having to get Twitter's go-ahead to grow any further.
Critics said it would stifle the development of innovative products.
The changes came as part of Twitter's overhaul of its Application Programming Interface (API).
An API allows different parts of a program to communicate together, as well as letting one application share content with another.
In Twitter's case, its API has allowed for the development of extremely popular third-party services like Hootsuite, Twitpic and Tweetdeck - which was acquired by Twitter in May last year.
Twitter says the new rules, announced by its director of consumer product Michael Sippey, aim to "deliver a consistent Twitter experience".
Mr Sippey wrote: "If you are building a Twitter client application that is accessing the home timeline, account settings or direct messages API endpoints (typically used by traditional client applications) or are using our User Streams product, you will need our permission if your application will require more than 100,000 individual user tokens."
In this context, "tokens" are individual users.
The guidelines also covered how tweets are displayed within apps.
"If your application displays Tweets to users, and it doesn't adhere to our Display Requirements, we reserve the right to revoke your application key," Mr Sippey explained.
The changes are not expected to have an immediate impact on users.
However, the announcement was heavily criticised by developers.
Marco Arment, creator of popular reading service Instapaper, advised developers who were building on Twitter to "start working on another product".
"Twitter has left themselves a lot of wiggle room with the rules," he wrote in a blog post.
"Effectively, Twitter can decide your app is breaking a (potentially vague) rule at any time, or they can add a new rule that your app inadvertently breaks, and revoke your API access at any time.
"Of course, they've always had this power. But now we know that they'll use it in ways that we really don't agree with.
"I sure as hell wouldn't build a business on Twitter, and I don't think I'll even build any nontrivial features on it anymore."
Twitter is not the only service to put such restrictions in place. Last year, Google announced that it would begin charging companies that made heavy use of its Maps product.