AliExpress Caught Using Inaudible Sounds for Browser Fingerprinting

A controversial and reportedly outdated technique involving inaudible sounds has been used to fingerprint web browsers, with the e-commerce giant AliExpress identified as employing this method. Browser fingerprinting is a privacy-invasive practice that allows websites to track users by collecting a unique set of characteristics about their device and browser configuration, even when cookies are disabled.

The use of inaudible sound waves, often referred to as "ultrasonic cross-device tracking," leverages the speakers on a user's device to emit high-frequency sounds that are imperceptible to humans. These sounds can then be detected by other devices or by the same device through its microphone, creating a persistent identifier that can link browsing activity across different sessions and potentially across multiple devices. While the technique is described as outdated, its continued use raises significant privacy concerns.