  We review the different options for resolution of the black hole loss of
information problem. We classify them first into radical options, which require
a quantum theory of gravity which has large deviations from semi-classical
physics on macroscopic scales, such as non-locality or endowing horizons with
special properties not seen in the semi-classical approximation, and
conservative options, which do not need such help. Among the conservative
options, we argue that restoring unitary evolution relies on elimination of
singularities. We argue that this should hold also in the AdS/CFT
correspondence.
