  We revisit the question of stability of holographic superfluids with finite
superfluid velocity. Our method is based on applying the Landau criterion to
the Quasinormal Mode (QNM) spectrum. In particular we study the QNMs related to
the Goldstone modes of spontaneous symmetry breaking with linear and quadratic
dispersions.In the linear case we show that the sound velocity becomes negative
for large enough superfluid velocity and that the imaginary part of the
quasinormal frequency moves to the upper half plane. Since the instability is
strongest at finite wavelength, we take this as an indication for the existence
of an inhomogeneous or striped condensed phase for large superfluid velocity.
In the quadratic case the instability is present for arbitrarily small
superfluid velocity.
