I know too much about how ad tech works. I’ve written code to de-anonymize all the data Google leaks through bid requests. Not individual credit card transactions, but enough to make me want nothing to do with them.

Ignorance is bliss as far as credit card companies go, I tell myself they sell anonymized transactions as csv dumps that aren’t tied to cookies etc. It’s probably worse than that. But if I really want to be anonymous, I pay cash.