When web browsers sense your presence

Proximity Sensor lets web sites to know when an object (i.e. you) is close to a device. I describe the privacy issues of proximity sensor in my analysis.

This example currently works best with a modern hardware such as Android device with Firefox Mobile browser. Proximity events are related to user's activity, such as:
  • User's hand-waving in front of a device
  • Placing a device close to your head. Are you sitting there at all? Ambient Light Sensor is a perfect proximity sensor
The sensor is usually physically located in your devices' upper region; try moving your hand close to it. If your device has a sensor and your browser supports it, you will see how the readout changes below (otherwise try Firefox Mobile on Android to get a feeling).
Min/Max proximity distance:

Min/Max time between consecutive events:

Event count:

Proximity readout change

Numbers of identical proximity events.

Proportion of readout of different type

Raw data readout: