[ThePhysicist]

I still see a lot of ways in which users could be de-anonymized, sometimes a single URL is already sufficient and side channels like the quorum mechanism might leak information as well. Maybe it's really anonymous, but personally I don't trust any mechanism that doesn't have a statistical anonymity guarantee, differential privacy being the preferred one as it's the only anonymity model that hasn't been broken yet.

Anyway, it's great that Cliqz did this work and I don't want to diminish it, I'm just very cautious when companies claim they're only collecting anonymous data, there were just too many cases in which promises have been broken.