  The Colombeau algebra of generalized functions allows to unrestrictedly carry
out products of distributions. We analyze this operation from a microlocal
point of view, deriving a general inclusion relation for wave front sets of
products in the algebra. Furthermore, we give explicit examples showing that
the given result is optimal, i.e. its assumptions cannot be weakened. Finally,
we discuss the interrelation of these results with the concept of pullback
under smooth maps.
