  An interesting concept in condensed matter physics is Planckian dissipation,
in particular its manifestation in a remarkable phenomenology of superfluid
density as a function of superconducting transition temperature. The concept
was ontroduced for $ab$-plane properties. However, when suitably interpreted,
it can also be applicable to the incoherent $c$-axis resistivity, which has not
been adequately addressed previously. There are two results in this note: the
first is a derivation using Kubo formula as to how Planckian dissipation could
arise. It is aided by the fact that the $c$-axis tunneling matrix element is so
small that a second order perturbation theory combined with presumed non-Fermi
liquid behavior is sufficient to illuminate the phenomonon. In addition, the
notion of quantum criticality plays an important role.
