  We study the hyperplane arrangements associated, via the minimal model
programme, to symplectic quotient singularities. We show that this hyperplane
arrangement equals the arrangement of CM-hyperplanes coming from the
representation theory of restricted rational Cherednik algebras. We explain
some of the interesting consequences of this identification for the
representation theory of restricted rational Cherednik algebras. We also show
that the Calogero-Moser space is smooth if and only if the Calogero-Moser
families are trivial. We describe the arrangements of CM-hyperplanes associated
to several exceptional complex reflection groups, some of which are free.
