Comment by eddyg
I still like to encourage people to watch all of https://www.youtube.com/watch?v=BLGFriOKz6U&t=1993s for the details (from Apple’s head of Security Engineering and Architecture) about how iCloud is protected by HSMs, rate limits, etc. but especially the timelinked section. :)
I still recommend Mr. Fart's Favorite Colors as a refutation, describing why all of these precautions cannot protect you in a real-world security model: https://medium.com/@blakeross/mr-fart-s-favorite-colors-3177...