  We prove that if $G$ is a countable discrete group with property (T) over an
infinite subgroup $H<G$ which contains an infinite Abelian subgroup or is
normal, then $G$ has continuum many orbit inequivalent measure preserving a.e.
free ergodic actions on a standard Borel probability space. Further, we obtain
that the measure preserving a.e. free ergodic actions of such a $G$ cannot be
classified up to orbit equivalence be a reasonable assignment of countable
structures as complete invariants. We also obtain a strengthening and a new
proof of a non-classification result of Foreman and Weiss for conjugacy of
measure preserving ergodic, a.e. free actions of discrete countable groups.

Operator Algebras