  We discuss some open problems concerning the origin and the emission
mechanism of gamma-ray bursts (GRBs) in light of recent developments. If GRBs
originate at extragalactic distances, we are facing four crises: (1) an energy
crisis, models have to account for more than 10^{53} ergs of energy emitted in
the gamma-ray energy band; (2) a spectral crisis, emission models have to
account for the surprising `smoothness' of GRB broad-band spectra, with no
indication of the predicted spectral `distorsions' caused by inverse Compton
scattering in large radiation energy density media, and no evidence for
beaming; (3) an afterglow crisis, relativistic shock models have to explain the
complexity of the afterglow behavior, the longevity of optical transients
detectable up to six months after the burst, the erratic behavior of the radio
emission, and the lack of evidence for substantial beaming as indicated by
recent searches for GRB afterglows in the X-ray band; (4) a population crisis,
from data clearly indicating that ONLY hard and long GRBs show a strong
deviation from an Euclidean brightness distribution, just the opposite of what
expected from extragalactic models without substantial cosmological evolution.
