Is it doable/possible for nodes to redact data (for instance inappropriate photographs) of their blockchain and stay a part of the community?
Sidenote:
Though OP_RETURN was supposed for embedding small quantities of knowledge, I imagine virtually all instances of embedding of photographs within the final 12 months use OP_FALSE OP_IF inside an in any other case regular script in a witness element. This avoids limitations imposed on OP_RETURN and features the Segwit low cost on transaction charges.
Censoring transactions:
Pruning nodes discard blocks which were validated and whose content material is not essential for sustaining UTXO state. It have to be possible to be selective and have particular standards to discard knowledge that’s undesirable. For Bitcoin Core I think about it’d necessitate rewriting massive blockfiles or some technique reminiscent of overwriting parts with say zeroes and updating indexes accordingly.
Not relaying unconfirmed transactions of this type has been prompt. As Michael Folkson commented, massive photographs (e.g. a number of MB) already cannot be relayed by Bitcoin core nodes due to its default coverage guidelines. publishers of enormous photographs must make direct preparations with miners.
Nonetheless, the above nonetheless requires that nodes obtain and validate new blocks, no matter content material, with a view to keep UTXO state. So the objective can’t be fully achieved.
I imagine it’s also computationally infeasible for regular nodes to tell apart inappropriate photographs from acceptable photographs. Moreover, Individuals who embed such photographs can take countermeasures to stop their detection.

