WHEN APPS WANTS to access data from your smartphone’s motion or light sensors, they often make that capability clear. That keeps a fitness app, say, from counting your steps without your knowledge. But a team of researchers has discovered that the rules don’t apply to websites loaded in mobile browsers, which can often often access an array of device sensors without any notifications or permissions whatsoever.
That mobile browsers offer developers access to sensors isn’t necessarily problematic on its own. It’s what helps those services automatically adjust their layout, for example, when you switch your phone’s orientation. And the World Wide Web Consortium standards body has codified how web applications can access sensor data.