  The Hawking radiation would make microscopic black holes evaporate rapidly
which excludes them from many astrophysical considerations. However, it has
been argued that the quantum nature of space would alter this behaviour: the
temperature of a Planck-size black hole vanishes and what is left behind is a
Planck-mass remnant with a cross-section on the order of $10^{-70}m^2$ which
makes direct detection nearly impossible. Such black hole remnants have been
identified as possible dark matter candidates. Here we argue that the final
stage of the evaporation has a recoil effect which would give the microscopic
black hole velocity on the order of $10^{-1} c$ which is in disagreement with
the cold dark matter cosmological model.
