Twitter has notified developers who build on the Twitter platform that they can't emulate the timeline function of Twitter since they would then resemble Twitter itself too closely. This comes after several third party Twitter apps being cut off from Twitter (essentially killing those apps) on Friday over what it said were concerns regarding user privacy and third party developers gaining access to the content of users' tweets.
It used to be that Twitter was more a platform than a business. People used a variety of third party apps to watch their Twitter feed. Twitter didn't even have an official app for mobile devices.
But now they do. And now Twitter says it wants users to use Twitter's own products. It says it won't approve any new third party clients and will hold the existing ones to high standards.
It's a sign of trying to make money off what they created but you wonder how much innovation will be strangled as a result.