The event horizon of a black hole appears to be plastered with 'afterimages' of everything that ever fell into it. (Because gravitational time dilation makes every such object appear to stop at the event horizon.) Now, suppose an event horizon is 'full' as defined by the Pauli exclusion principle. If one more fermion falls into the black hole, would its afterimage violate the exclusion principle? I think maybe, by the following reasoning. The event horizon radius is proportional to the black hole's mass. If an object of x% of the black hole's mass falls in, the event horizon radius increases by x%. The volume of an infinitesimally thin shell at the event horizon increases by x% cubed. The volume of an object of a given mass depends on its density, which, for a proton is E18 kg/cubic meter. The average density of the volume inside the event horizon of a one solar mass black hole is 1.85 E19. Thus, in this case, it wouldn't fit, so would try to violate Pauli. What would happen? There are cases where Pauli gets violated, for example, the collapse of a white dwarf to a neutron star. For black holes exceeding about 20 solar masses there would be no problem. Electron density is not well defined, so I don't know what would happen in the case of an electron. Your comments please.