Everybody acts like tech companies get tremendous value from analyzing PII. Almost all of tech (perhaps excluding fb) mostly just collects pii because it's easier to do so than not, and because everybody else is. If it were banned in a clear sensible way worldwide I don't think the tech would suffer much.
The revenue difference I have heard, ballpark, for targeted advertising (based on tracking) on the web, en masse is 2x. So the gajillion dollar online ad industry would only be set back by 4 or 5 years. So, 2018? Not bad. I say, do it. Ban targeted advertising on the web.
While it is mildly interesting, I've never read any articles, studies,or other info that the highly touted promise of PII to increase sales, effectiveness of advert spending, or ad relevancy for consumers is anything but a complete flop. Decades of effort by the top tech firms and investors, and contextual ads are still more relevant -just show ads quasi-related to what I'm reading/viewing right now.
Highly likely that Google could this afternoon vaporize every byte of PII they hold and be just fine. FB might suffer, but more because surveillance tech is their core worldview then that they couldn't survive.
If they are smart ,they'll vaporize it this week, without any legislation. But I'm not counting on it.