Lots of things start out like this, then later they start looking for or blocking other things. Pirated movies, files leaked from three letter agencies, a picture of the president with a ** in his mouth, etc. Even if this is 100% bullet-proof it is still enough that Apple should be seen as privacy invading and leaking everything to the government (and others later on) as it will be abused if implemented everywhere. This isn't irrelevant because of other things happening that are also bad. This is added on-top of those broken system, like the ones in the US you mention.