I've heard this called a "pool pissing attack," as in peeing in the swimming pool, and it's already been done to some block chains, which contain CP and other i

I've heard this called a "pool pissing attack," as in peeing in the swimming pool, and it's already been done to some block chains, which contain CP and other illegal stuff. One mitigation I've used in one project is to hash records by hashing hashes of their fields, permitting record fields to be selectively deleted from storage (e.g. by a blacklist) without breaking data structure validation capability.