Ever since Microsoft revealed a Kinect 2.0 is included with each Xbox One sold, rumors have flown over what the company can and/or will do with the information its sensors pick up. The software giant's overarching privacy statement makes its case that you shouldn't have anything to worry about. That's because the info Kinect's unblinking eye gleans either never leaves your console, or in the case of "expression data" it's destroyed once you turn the system off. Furthermore, you can manually dive into the system settings and nuke all the locally cached data whenever you want.
Voice command samples can go back to Redmond for "system improvement" with a choice to opt-out, just like the current Kinect. However, the company claims that in-game voice chat can be monitored "to the extent permitted by law," but it can't monitor all users and won't make an attempt to. Microsoft even went out of its way to point out that the One can't listen in on Skype calls -- anyone think that's enough to keep prying eyes out of their video chats?
Microsoft Xbox One