  The empirical relationship between the broad line region size and the source
luminosity in active galactic nuclei (AGNs) is used to obtain black holes (BH)
masses for a large number of quasars in three samples. The largests BH masses
found exceed 10^{10} Msun and are correlated, almost linearly, with the source
luminosity. Such BH masses, when converted to galactic bulge mass and
luminosity, indicate masses in excess of 10^{13} Msun and sigma(*) in excess of
700 km/sec. Such massive galaxies have never been observed. The largest BHs
reside, almost exclusively, in high redshift quasars. This, and the deduced BH
masses, suggest that several scenarios of BH and galaxy formation are
inconsistent with the observations. Either the observed size-L relationship in
low luminosity AGNs does not extend to very high luminosity or else the
M(BH)-M_B(bulge)-sigma(*) correlations observed in the local universe do not
reflect the relations of those quantities at the epoch of galaxy formation.
