[swores]

I completely disagree, and I'm someone whose interests would be best served by agreeing with you (my marketing agency spends a lot on advertising, and if the ad platforms don't have to enforce this sort of bad behaviour from other advertisers then prices could potentially fall as their expenses would)

Google's ad network isn't just dumb pipes for information like an ISP or an electricity provider, they're actively charging companies money in order to send whatever information to be displayed and code to be executed those companies want them to onto the screens of people that they're actively targeting. It should absolutely be Google's (or whatever ad network's) responsibility to not allow bad actors to use their services to spread viruses/malware, nor to allow even worse privacy evasion that they're already doing themselves such as allowing fingerprinting.