Bitcoin’s security risk starts when one block gets far more fees than the next

When a single Bitcoin block carries dramatically higher fees than adjacent blocks, it creates strong economic incentives for miners or rented-hashpower attackers to attempt targeted reorgs to capture those fees. The potential reward from replacing one high-fee block can outweigh the cost of short reorgs, increasing the practical attack surface even without a sustained majority of hashpower. This concentration of fees raises the likelihood of transient chain reorganizations and weakens transaction finality, a risk that grows as block subsidy dwindles and fees become a larger share of miner revenue. Monitoring fee distribution and addressing incentives that favor fee-targeted attacks will be increasingly important for Bitcoin’s security.