  A number of observations hints for the presence of an intermediate mass black
hole (IMBH) in the core of three globular clusters: M15 and NGC 6752 in the
Milky Way, and G1, in M31. However the existence of these IMBHs is far form
being conclusive. In this paper, we review their main formation channels and
explore possible observational signs that a single or binary IMBH can imprint
on cluster stars. In particular we explore the role played by a binary IMBH in
transferring angular momentum and energy to stars flying by.
