iMessage isn't spying on you. There are two aspects to the scanning. One is if you use iCloud. The other is if you send photos to a minor via iMessage.
If you get flagged by the iCloud scanning, you could be reported to the authorities. But you can opt out of iCloud scanning by not using iCloud.
If you get flagged by the iMessage system, you are not reported to the authorities. The parents of that person may receive a notification. But if you are sending photos to a kid on a device set up by their parents, you should pretty well expect that photos you send may be seen by their parents.
I understand the privacy concerns raised by Apple's about-face here. But we should be clear about what is and isn't happening.
WhatsApp comes off looking like a defender of privacy by saying "we won't do what Apple has done" but in reality the most objectionable thing Apple is doing relates to cloud-based photo storage, not messaging. The messaging piece is a new type of parental controls and does not involve the authorities in any event.
If you read GP's comment, it conflated these two issues as if they both applied to iMessage. The point is that you don't have to opt out of iMessage to avoid being reported to the authorities. You just have to not use iCloud, a system that has many excellent competitors. You can also roll your own. This is not as big a deal as if one of the major messaging systems were snooping through all your messages and photos. That is what GP made it sound like.
How do you know? Apple makes a lot of claims about their security but these claims probably don't preclude Apple spying on you somehow. Especially if a warrant compels them.
If you get flagged by the iCloud scanning, you could be reported to the authorities. But you can opt out of iCloud scanning by not using iCloud.
If you get flagged by the iMessage system, you are not reported to the authorities. The parents of that person may receive a notification. But if you are sending photos to a kid on a device set up by their parents, you should pretty well expect that photos you send may be seen by their parents.
I understand the privacy concerns raised by Apple's about-face here. But we should be clear about what is and isn't happening.
WhatsApp comes off looking like a defender of privacy by saying "we won't do what Apple has done" but in reality the most objectionable thing Apple is doing relates to cloud-based photo storage, not messaging. The messaging piece is a new type of parental controls and does not involve the authorities in any event.