I thought the App Store review guidelines explicitly prohibit hidden features and using public APIs outside their intended purpose. Is audio-based fingerprinting just not something review can realistically catch?

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ValdikSS 4 hours ago | parent | next [-]

They probe all audio devices, including microphones, which probably temporarily switches Bluetooth devices into HPF mode due to how Bluetooth duplex audio works.

I'd argue it's "silent" though: aliexpress wakes up my audio card if nothing plays, which results in a very faint "pop" sound every time I open the tab.

It's been this way for ~3+ years at least.

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lapcat 3 hours ago | parent | prev [-]

It's the website.

The title of the article literally mentions "WebAudio", and the first paragraph states that the author is using a PC. The second paragraph mentions Chrome and Firefox.

Apple and the App Store have zero involvement here.

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hunter2_ 2 hours ago | parent [-]

This is a huge stretch, but if this problem exists in not only the PC versions of Chrome/Firefox but also the Android/iOS versions, then theoretically the app store reviewers could flag the browsers for facilitating this behavior against app store guidelines. In practice, apps of such caliber as popular browsers might be a bit above such reviewers' pay grade, so to speak.

	▲	lapcat 2 hours ago \| parent [-]
		> This is a huge stretch This is nonsense. Safari also supports Web Audio. Safari does not, however, support Microsoft Windows, which is why the article author didn't mention it. Moreover, all web browsers on iOS have to use Apple WebKit, so Web Audio support is not actually the fault of the non-Apple browser vendors.