  The recent detection of gamma radiation from Mkn 501 at energies as high as
25 TeV suggests stringent upper bounds on the diffuse, far infrared,
extragalactic radiation density. The production of electron-positron pairs
through photon-photon collisions would prevent gamma photons of substantially
higher energies from reaching us across distances of order 100 Mpc. However,
coherently arriving TeV or sub-TeV gammas - Bose-Einstein condensations of
photons at these energies - could mimic the Cherenkov shower signatures of
extremely energetic gammas. To better understand such events, we describe their
observational traits and discuss how they might be generated.
