Weeks after promising that its fitness-tracking application wouldn't share data with Facebook after it was acquired by the company, Moves has updated its privacy policy to allow information sharing with partner companies "including, but not limited to, Facebook."

The companies continue to claim that they aren't "commingling" the data gathered from Moves, which counts steps with a smartphone's built-in sensors, with the troves of data Facebook has amassed on its own. But as the Center for Digital Democracy's Jeffrey Chester explains to the Wall Street Journal, the difference between "commingling" and "sharing" data is little more than semantic obfuscation. (That seems to have become quite the trend of late.)

The updated privacy policy means that Facebook now has a way to measure every step Moves users take -- and, assuming the company plans to build similar features into its own software, could eventually count the steps of some 1 billion people. It's unclear how that data could help Facebook in the short-term, but the company has seldom concerned itself with present utility. Data is to Facebook as profits are to Amazon: the company is more focused on creating the tools that will eventually lead to a return on the investment than it is on immediate benefits.

It matters little if Facebook never finds a purpose for the information it gathers from Moves. The company has spent billions of dollars on acquisitions in the last few months alone -- the amount it paid for Moves almost certainly pales in comparison to what it paid for WhatsApp or Oculus. This is a small investment in a nascent product category that will allow Facebook to experiment with fitness tracking without having to build something like Moves on its own.

But the decision to change Moves' privacy policy shortly after the company promised its users that it would continue to keep their data away from Facebook's makes it even harder to trust the promises of companies that have just sold themselves to the greatest data vacuum in the world. These companies should remember that they can't promise anything to their users -- after the deals have been signed, they no longer have control over what "their" company does.

Maybe the companies will keep their word and prevent Moves data from being combined with Facebook data to serve more relevant ads. And maybe Facebook can show that it's not an information-obsessed parasite sucking data from any source it can find -- but changing the privacy policy of an application that literally measures every step you take weeks after its parent company assured its users that nothing would change isn't going to help Facebook make that point, or instill trust in future purchases.

[Illustration by Hallie Bateman]