  The shear viscosity bound violation in Einstein gravity for anisotropic black
branes is discussed, with the aim of constraining the deviation of the shear
viscosity-entropy density ratio from the shear viscosity bound using causality
and thermodynamics analysis. The results show that no stringent constraints can
be imposed. The diffusion bound in anisotropic phases is also studied.
Ultimately, it is concluded that shear viscosity violation always occurs in
cases where the equation of motion of the metric fluctuations cannot be written
in a form identical to that of the minimally coupled massless scalar fields.
