Researchers found that both #Meta snd #Yandex link(ed) IDs between browsers and their native apps by local communication on #Android devices.
E.g. the #Facebook app registered a local service when launched on Android. Millions of web pages including the Meta Pixel tracking script would then send their (first-party) cookie value to the app. The app would then send this value to Meta, paired with the FB username.
Essentially deanonymizing the Meta Pixel.
h/t adfichter 🖋 (npub1uuv…lg4c)
https://localmess.github.io/
Marcel Waldvogel
npub1p0…agzg8
2025-06-04 03:46:11 UTC
Author Public Key
npub1p0hkce7e088f6d59qva0s4t5ga823ks06h4huwn90egnd79w9nts9agzg8Seen on
wss://relay.momostr.pinkPublished at
2025-06-04 03:46:11 UTCEvent JSON
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"pubkey": "0bef6c67d979ce9d3685033af85574474ea8da0fd5eb7e3a657e5136f8ae2cd7",
"created_at": 1749008771,
"kind": 1,
"tags": [
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[
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"web"
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"content": "Researchers found that both #Meta snd #Yandex link(ed) IDs between browsers and their native apps by local communication on #Android devices.\n\nE.g. the #Facebook app registered a local service when launched on Android. Millions of web pages including the Meta Pixel tracking script would then send their (first-party) cookie value to the app. The app would then send this value to Meta, paired with the FB username.\n\nEssentially deanonymizing the Meta Pixel.\n\nh/t nostr:npub1uuvtzc0zr4m2x8xmammaxpf9892mhvm9r4nv6qcz84fh0rywel9sf8lg4c \nhttps://localmess.github.io/",
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}