  The idea that dark matter could be made of stable relics of microscopic black
holes is not new. In this article, we revisit this hypothesis, focusing on the
creation of black holes by the scattering of trans-Planckian particles in the
early Universe. The only new physics required in this approach is an unusually
high-energy scale for inflation. We show that dark matter emerges naturally and
we study the question of fine-tuning. We finally give some lines of thoughts
for a possible detection.
