  We relate the three-dimensional infinite momentum frame spatial charge
density of the pion to its electromagnetic form factor. Diverse treatments of
the measured form factor data including: phenomenological fits,
non-relativistic quark models, the application of perturbative QCD, QCD sum
rules, holographic QCD, and the Nambu Jona-Lasinio (NJL) model all lead to the
result that the charge density at the center of the pion has a logarithmic
divergence. Relativistic constituent quark models do not display this
singularity. Future measurements planned for larger values of momentum transfer
may determine whether or not a singularity actually occurs.
