I used to work at Mozilla until recently and what you're talking about is nonsense. The telemetry data is handled extremely carefully. Any downstream use of that data is also carefully managed so that creating re-identifiable data is not possible.

Could Mozilla reidentify people with raw telemetry - sure. Is it easy or done in practice - no. Shut the hell up unless you know better than someone who has handled that data.

Seriously folks - Mozilla has problems - but proper handling of your private data is not one of them.