Stanford’s researches at the Stanford Security Laboratory discovered many security vulnerabilities in sensor arrays endemic to most smartphones. According to them, accelerometers, speakers and microphones can be uniquely identified with specific devices, functioning in the same way that cookies do and they can’t be turned off.
They discovered that microphones and speakers have unique frequency response curves, which can be used to tag devices. Each accelerometer has unique imperfections that differ from device to device. A website can read accelerometer’s motion, identify its „fingerprint“ and assign it a tag, which website can store on its own servers, allowing it to track the device. It is not clear if this method is already in use by advertising companies, spy agencies or other companies, but because Stanford researches discovered it means it is likely that also others discovered this.
Via: slashgear