Google. RIM. Apple. Amazon. All four companies find themselves in the privileged position of running the platform that powers various devices, and this week, they've all encountered the complexities of their gatekeeper status. A post on the Future of the Internet blog highlights exactly what that means for you and your phone or iPad or Kindle.

In the end, all four platforms decided what exactly their users own. Users buy a device, but what that device actually does is a service controlled by the platform. This service is subject to change at the platform's discretion if, for example, it harms the device or doesn't fit the company's business model - and subject to change if senators, courts, advocacy groups, or anyone else can pressure the platform to take action.

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