It's amazing to me that an advert can run arbitrary javascript at all. It wasn't long ago that this would have been seen as a massive security risk by site owners and ad platforms alike. I'll give them the benefit of the doubt and assume that perhaps it's a structured service provided by the ad network, and the ad buyer just checks a box. But as a site owner even that would be too much for me.

I've been playing around with ideas about more ethical analytics and advertising, and I think they're pretty easily built platforms. But the question is are they marketable? Would GloboCorp and MarketingCo give up the ability to track consumers so closely in favor of a more ethical approach, or has it been too valuable for them to give up?