[joe_the_user]

"How is this iCloud specific?"

In case you didn't the topic, what is specific (for now, for now...)to iCloud/apple is the "we're scanning your photos on your device and maybe reporting them if they're bad" approach. So you get the local hashes on the supposedly encrypted files and you get the situation of local files trigger global effects like the police swooping down and arresting you. So that's why despicable and hair-brained scheme in specific produces a greater "attack surface" in multiple ways.

And again, sure, Apple doing this quite possibly will set a precedent for Google et al to answer the other ambiguous meanings your ambiguous comment has.