The system is used during synchronization to iCloud Photos, which is an optional feature. Other hosting providers do similar scans, but they do not do them wit

The system is used during synchronization to iCloud Photos, which is an optional feature. Other hosting providers do similar scans, but they do not do them within the client-side component. Presumably, this is done to give the hosting environment no access to the actual data (e.g. data access such as by subpoena becomes a cross-organizational auditable event)