So, I'm not claiming it's a threat to bitcoin or that we should design bitcoin around it. I realize there are people taking those positions, though.

When you ask "to what end?", isn't it the same as whyever people broadcast this stuff over any other network. As to who is scanning for it, the answer would presumably be whoever is seeking to use the network for this purpose.

There are lots of people who consume and share child pornography already. I don't understand why they wouldn't use our network to freely broadcast it, if that's an option. Supposedly, that's exactly what happened to BSV when they increased the amount of arbitrary data that could be included.

I can't at all speak to the technical difficulties or ease of actually viewing such data as an image.