Pre core 30 thinking the situation before the change through.

Miners offering large op_returns scan them for illegal content. Makes sense. If MARA accepts CSAM we can all see that it went into the block they mined and was non standard. Legally very risky for them with a permanent public immutable record that it came from them.

Only if others start relaying large op_returns do the large pools offering this service have deniability that maybe the illegal content came from the wider mempool somewhere.

That means before core 30 you need to basically run your own anonymous service for your own configurable block templates and then mine a block if you want to put CSAM on chain and maybe get away with it.

Follow so far?

That means that before core 30 the easiest way to put CSAM on the blockchain is Ocean, DATUM, and Knots combined with a hash rate for hire service.

RIP my replies.