[thw0rted]

Dumb question: do we know from what they've released publicly if it will be possible for security researchers to snag a copy of the database, perform the same perceptual hash algorithm on a given image, and determine if there's a "hit", without violating some kind of license term?

Perhaps the community could run a crowdsourced "keep them honest" service web service -- upload the latest illegal-in-China Winnie-the-Pooh meme, oh hey look at that, it's in the China-only version of the database, isn't that weird, etc etc. (Obviously you wouldn't want people "testing" images that are in the database for the actual stated purpose...)