  One can increase one-quarter the area of a black hole, A/4, to exceed the
total thermodynamic entropy, S, by surrounding the hole with a perfectly
reflecting shell and adiabatically squeezing it inward. A/4 can be made to
exceed S by a factor of order unity before the shell enters the Planck regime,
though practical limitations are much more restrictive. One interpretation is
that the black hole entropy resides in its thermal atmosphere, and the shell
restricts the atmosphere so that its entropy is less than A/4.
