Checking for CSAM isn't the issue. The issue is that Apple's system design easily extends to checking all sorts of other things - political dissidents, journalists, etc.
Not only that, it commits a felony when it transmits found CSAM to a party other than NCMEC (i.e. Apple itself).
Not only that, it commits a felony when it transmits found CSAM to a party other than NCMEC (i.e. Apple itself).