  In theories with a large number N of particle species, black hole physics
imposes an upper bound on the mass of the species equal to M_{Planck}/\sqrt{N}.
This bound suggests a novel solution to the hierarchy problem in which there
are N \approx 10^{32} gravitationally coupled species, for example 10^{32}
copies of the Standard Model. The black hole bound forces them to be at the
weak scale, hence providing a stable hierarchy. We present various arguments,
that in such theories the effective gravitational cutoff is reduced to
\Lambda_G \approx M_{Planck}/\sqrt{N} and a new description is needed around
this scale. In particular black-holes smaller than \Lambda_G^{-1} are already
no longer semi-classical. The nature of the completion is model dependent. One
natural possibility is that \Lambda_G is the quantum gravity scale. We provide
evidence that within this type of scenarios, contrary to the standard
intuition, micro black holes have a (slowly-fading) memory of the species of
origin. Consequently the black holes produced at LHC, will predominantly decay
into the Standard Model particles, and negligibly into the other species.
