AliExpress Fingerprinting Exposed Browser Audio Side Effects
Matt Callaghan found AliExpress pages using obfuscated WebAudio code to fingerprint browsers, and the effect was visible outside the browser: his multipoint Bluetooth headphones stopped handing audio back to his phone. He said the behavior showed up in Firefox and Chrome, and closing the AliExpress tab restored normal audio switching immediately.
The page builds a silent audio graph with a sawtooth oscillator, an analyser, and zero gain. Nothing audible plays, but the browser still processes the signal, and the script reads the tiny differences that processing leaves behind as a fingerprint. Because there is no media element to mute, tab muting does not stop the work.
For browser vendors and privacy teams, the important point is that WebAudio can be a tracking surface even when a page looks silent, and that surface can have user-visible side effects. If your anti-tracking model assumes only visible media or audible playback, this case shows the browser can still do enough work to affect peripheral behavior.