The entire technical underpinnings of this solution rely on essentially neural image embeddings, which are very well known to be susceptible to all sorts of clever attacks. Notice how within a day or two of the announcement of this whole system and it's symbols, people were already finding lots of 'hash' collisions.
In the space of people and places that can train and implement/serve such embeddings, these issues are pretty widely known, which makes it very non-obvious how this happened IMO. Someone that understood all of these issues seems to have directly ignored them.
More importantly hash collisions result in manual review by humans at Apple, hardly a major issue. This is also a safety measure protecting users from political images being tagged in these database.
The backlash was obvious from the outside, but it’s clear someone spent a lot of time building something they felt was reasonable. Even if Apple presumably just implemented the same system in iCloud, at least people became aware governments have access to such systems.