  Astrophysical high-energy neutrinos observed by IceCube are sensitive to
small effects in a vacuum such as those motivated from quantum gravity
theories. Here, we discuss the potential sensitivity of Lorentz violation from
the diffuse astrophysical neutrino data in IceCube. The estimated sensitivity
reaches the Planck scale physics motivated region, providing IceCube with real
discovery potential of Lorentz violation.
