I consume a lot of video for work. My viewing is frequently interrupted by phone calls, dogs, delivery people hitting the buzzer, etc. Each time this happens I reflexively hit the spacebar to pause the video--and instead the browser window scrolls down half a screen while the video continues to play.
German developer Mattias Hemmingsson has a workaround--but one that I'd never consider using. By tapping into the Chrome browser's FaceDetector API (application programming interface), Hemmingsson has created an extension called FacePause. As you've probably surmised, it uses your camera to detect when you look away, and automatically pauses whatever video you're watching.
I think a lot of people, especially those enamored of technology, would happily use this. I'm always surprised by how much privacy people are willing to trade away for the sake of "convenience," like having a microphone/speaker in your house that's connected to the internet. It recently made the news that an Amazon Echo mistakenly recorded a couple's private conversation in their home, and sent it to someone on their contact list.
The cameras on my computer set-up are covered, and the mic is muted, unless I have a Skype meeting. I can't imagine a single convenience that would prompt me to do otherwise. Not being able to pause video correctly is a minor annoyance to me, not a dealbreaking hassle.
My question to you designers is: When does attention to UX go too far? From a functional perspective, FacePause is undeniably a clever use of technology that confers a benefit, however small. Is it too small to justify the cost of privacy? If so, would you use it if, for example, it somehow saved you money, or if the developer paid you to try it out for a month to give feedback?
Not that Hemmingsson would ever do such a thing. "I don't trust my webcam," he told Gizmodo, "so I have it covered and I don't trust Youtube/Google so see this more as an experiment of Chrome's new technology, than a product you'd use every day."