Remember how Netflix can conduct all sorts of strange tests to research ways it can improve its service? Well, it turns out that access to the physical activity data that your Android phone tracks can be a great asset for Netflix, so the company wants permission to track that data.

A Netflix user got a prompt from the Android Netflix app that asked him whether or not he was willing to share physical activity data with the app.

The Next Web discovered that it wasn’t a mistake, with Netflix confirming the feature:

We are continually testing ways to give our members a better experience. This was part of a test to see how we can improve video playback quality when a member is on the go. Only some accounts are in the test, and we don’t currently have plans to roll it out.

The explanation does make some sense, given that many people use Netflix on their mobile devices while on the go. In fact, Netflix just launched a mobile-only plan in India.

Netflix might have reasons to dig into your movement so that it can optimize streaming on phones as signal quality changes. For example, Netflix might analyze your commute data, assess cellular coverage, and then determine whether it has to preload content on your phone or tablet in the background. That way you’d have it ready to watch whenever you open the app again. This is just speculation though, as Netflix hasn’t explained the specifics of what it’s doing with activity data during this test.

Just because some Android users received the prompt, doesn’t mean that everyone using Netflix on Android will. Also, it’s unclear how long the test will last or if the test will expand. As for iPhone, there’s no such test being conducted with the iOS Netflix app for the time being.