Locality inside black holes violates the second law of thermodynamics

We show that the entropy created by Ohmic dissipation inside an accreting charged black hole may exceed the Bekenstein-Hawking entropy by a large factor. Since only the Bekenstein-Hawking entropy is released during evaporation, the black hole appears to destroy entropy. To avoid this startling result, the interior of the black hole must contain a proliferation of complementary causal patches — spatially separated regions that are complementary descriptions of the same degrees of freedom. No single observer sees a violation of the second law, and Bousso’s covariant entropy bound, which does not add entropy between different causal patches, is respected.