  We study the impact on the trajectory of high-energy cosmic-ray protons of
scattering off the cosmic dark matter. We compute the scattering angle as a
function of the cosmic-ray energy, of the dark matter mass, and of the
interaction strength for a few representative choices for the relevant
interaction cross section. We find that the typical deflection angle over the
cosmic ray path is largely independent of the dark matter mass. Given existing
limits on the interaction strength, we compute the average deflection angle. We
find that for large interaction cross sections and low cosmic ray energies, the
predicted deflection angle is much larger than the angular resolution of very
high-energy cosmic-ray observatories such as Pierre Auger.
