  We present the results of a deep radio observation of the globular cluster
NGC 2808. We show that there are no sources detected within the core of the
cluster, placing constraints on both the pulsar population of the cluster and
the mass of a possible intermediate mass black hole in NGC 2808. We compare the
results for this cluster with other constraints on intermediate mass black
holes derived from accretion measures. With the exception of G1 in M~31 which
has previously shown radio emission, even with considerably more conservative
assumptions, only the clusters with the poorest of observational constraints
are consistent with falling on the $M_{BH}-\sigma$ relation. This result is
interpreted in terms of the fundamental differences between galaxies and
globular clusters.
