seasion ids are unique? are they personal data if you cannot link them to an individual? count those. let’s say you are paranoid and someone, somewhere can link those random ids to people. So hash those random ids with a key that this someone has no access to. Now you have anonymized ids you can count uniquely and that cannot be linked to individuals.
You can anonymize data if you really want to and use it for understanding trends, usage etc in a privacy respectful way. Few companies bother these days though. And yes if you want a 100% watertight way, it’s hard.
