[gbrown]

Anonymous data is one identifier or clever match away from identification. This is particularly severe for sites/services/hardware that records audio (man, who would knowingly allow that kind of abuse??), but it can apply to mouse tracking too. Mouse tracking fingerprints could be used to re-identify all sorts of other things.

[code_duck]

It depends how much data is collected in the first place, and how much is available to the person trying to break anonymization. If I'm not mistaken, everything is deanonymizable with global traffic analysis.