And how good is NCMEC's security? How resistant to hacking/tampering is the hash database at the source?Yes exactly. They'll presumably be divergence unless this database is international.
"“And God spake all these words, saying,...”Geez. "And" is a conjunction, not a subject. You don't start sentences with conjunctions. Wow, what has happened to our spoken language these past 10 years? Are copywriters that dang lazy or ignorant when to detect someone speaking a run-on sentence? Can people no longer form coherent sentences?
-- King James Bible, Exodus 20:1
Good enough for Moses, good enough for me.