  We present a theory for the photon energy and polarization dependence of
ARPES intensities from the CuO$_2$ plane in the framework of strong correlation
models. We show that for electric field vector in the CuO$_2$ plane the
`radiation characteristics' of the $O$ $2p_\sigma$ and $Cu$ $3d_{x^2-y^2}$
orbitals are strongly peaked along the CuO$_2$ plane, i.e. most photoelectrons
are emitted at grazing angles. This suggests that surface states play an
important role in the observed ARPES spectra, consistent with recent data from
Sr$_2$CuCl$_2$O$_2$. We show that a combination of surface state dispersion and
Fano resonance between surface state and the continuum of LEED-states may
produce a precipitous drop in the observed photoelectron current as a function
of in-plane momentum, which may well mimic a Fermi-surface crossing. This
effect may explain the simultaneous `observation' of a hole-like and an
electron-like Fermi surfaces in Bi2212 at different photon energies. We show
that by suitable choice of photon polarization one can on one hand `focus' the
radiation characteristics of the in-plane orbitals towards the detector and on
the other hand make the interference between partial waves from different
orbitals `more constructive'.
