  Israel's proof of the third law of black hole dynamics is based on the
semi-rigidity assumption which requires that the areas of the outermost trapped
surfaces are preserved. We argue that the condition that the area of the event
horizon should not decrease is necessary -but not sufficient- for the
semi-rigidity assumption to hold. It is known that the presence of a naked
singularity in the exterior region invalidates Hawking's proof of the area
theorem. In this sense, the third law assumes the validity of the strong form
of the cosmic censorship conjecture, contrary to general acceptance. Still, one
cannot guarantee that the semi-rigidity assumption holds. Therefore the current
proof is incomplete. Recent studies on the interactions of black holes with
fermionic fields imply a generic formation of naked singularities. The presence
of these singularities invalidates the laws of black hole dynamics and cosmic
censorship conjecture for the processes that satisfy the weak energy condition.
