Social networks like Facebook keep far more information than any ad network. Most networks usually purge data beyond 30-60 days because it is no longer relevant for targeting. And Facebook doesn't have to scrape any info since people supply it willing.
My point: Privacy issues are somewhat pointed at the wrong institutions who really aren't a threat.
I think you skipped the part that ad networks only keep about 30-60 days of data. Keeping things forever doesn't help when targeting ads to user intent, which changes pretty frequently. It's also anonymized and we don't have personal information like names or addresses. You're also discounting the value it brings to lots of consumers, marketers and website publishers alike to have relevant messages.
I really dont understand this argument of privacy as if everyone was living off the grid somewhere. What is the impetus here? And in context of web publishers, if you dont want ads then you'd have to pay for content directly, which is no more private and in fact reveals even more info.
The reason you use a credit card and not cash during real transactions is because you care more about value and convenience than privacy, so why are ads online such a target of all this?
Look, I'm one of those few people that likes ads. I get how ads subsidizes free things, but well, it doesn't really matter because I like good ads by themselves.
Yet, I block ads on most sites because I don't like being tracked. The argument is quite simple. I don't know you (ad network), and I don't want you to watch everything I do. I'm pretty sure you won't do anything bad with that data, but I don't like it anyway.
I'm quite ok with my bank knowing what I spend money on, because I do know them, I have a choice on what bank to use, and because the service they provide me does require that data. None of that is exactly true for ads.
My point: Privacy issues are somewhat pointed at the wrong institutions who really aren't a threat.