[smsm42]

So they'd just compare two small very blurry thumbnails? Not sure that makes it any better.

[zepto]

It’s not literal blurring - it’s a transform that means you don’t see the actual image, but you do see features and detail that lets you easily tell two source images apart.

The point is that you aren’t looking to see if there is porn in the image. You are looking to seem if the image matches the porn image.

It’s a good mechanism.