We compute the mutual information of two Hawking particles emitted consecutively by an evaporating black hole. Following Page, we find that the mutual information is of order exp(-S) where S is the entropy of the black hole. We speculate on implications for black hole unitarity, in particular on a possible failure of locality at large distances.
Iizuka, N., & Kabat, D. (2013). Mutual information in hawking radiation. Physical Review D - Particles, Fields, Gravitation and Cosmology, 88(8) DOI: 10.1103/PhysRevD.88.084010