Earlier quoted context omitted.
> Fraud prevention for example will get an order of magnitude harder, First Ad Fraud != Fraud. It is low grade hacking. Second. Trading the privacy of every iPhone user so that advertisers can prop up a sketchy/ poor industry is a terrible trade.
This completely changes the game on all kinds of fraud, not just ad fraud. Currently when you get caught, the service you’re abusing bans your device. To keep trying you need new hardware; attacks have a real monetary cost for the attacker. When your iPhone can present itself as infinitely many iPhones, this is neutered, and services will need different (probably more invasive) techniques to keep banned users away.
Apple already has a privacy-preserving solution for that: