> Mining Ethereum doesn’t allow for much inspection of what you’re validating in each block. Yes and no. It depends on what you mean by “validating”. If your

> Mining Ethereum doesn’t allow for much inspection of what you’re validating in each block. Yes and no. It depends on what you mean by “validating”. If your objective is to restrict the types of transactions that end up in the blocks you yourself create, you can recompile geth with a custom mempool implementation, and use that custom mempool to inspect the data of any pending transaction you want. This is how MEV works. In other words, it is 100% possible for a technically-competent miner to only create new blocks that exclude blacklisted accounts, or that restrict transactions according to any number of criteria. On the other hand, once a new block has already been mined and propagated to the network, there is nothing that a single miner can do to stop it. If you start rejecting otherwise-valid blocks because they include blacklisted transactions, you will only fork yourself from the network. The rest of the miners will keep on building on top of the block you wanted to drop.