In July 2019, an anonymous BSV transaction embedded CSAM images in a ~100KB OP_RETURN output (pre-Genesis, when BSV allowed ~100KB, similar to BTC v30 now). The block was mined, making the content immutable and queryable via explorers (e.g., Blockchair). Exact txid wasn’t widely publicized for ethical reasons, but CoinGeek and BSV Wiki confirmed it.

Interpol and EU Authorities issued a notice in late 2019 urging BSV node operators to filter or prune the content.

BSV has an unlimited OP_RETURN field.

Governments that want to prosecute someone for something will find a way.