This is not only incorrect (this particular law doesn’t apply here), but I can easily prove it beyond any shadow of a doubt.

backpage.com was shutdown despite their willingness to comply with the law because they were found to “facilitate” CSAM. Omegle was also temporarily shutdown for the same reasons. There have also been quite literally dozens of prosecutions of website admins on the dark web for offering a platform for CSAM despite them arguing in court that they had no control over what their users uploaded and quickly moderated the content when discovered. In the end none of it matters–as a provider of a service you are required to make it difficult to share CSAM, not just comply with the law when someone catches you with your pants down.

It bedevils me that people are so laissez-faire about literal fucking CP–AI generated or not.

And in spite of literally all of that, none of this has anything to do with US law. It’s Patron policy. They don’t want to service someone who constantly has issues with CSAM, and they have every right not to offer their services to catbox.