  We discuss a new superfluid instability occuring in the interior of mature
neutron stars with implications for freely precessing neutron stars. This
short-wavelength instability is similar to the instability which is responsible
for the formation of turbulence in superfluid Helium. Its existence raises
serious questions about our understanding of neutron star precession and
complicates attempts to constrain neutron star interiors using such
observations.
