Comment on ``Vanishing Hawking Radiation from a Uniformly Accelerated   Black Hole'', P. Yi, Phys. Rev. Lett. 75 (1995) 382
  We argue that the analysis of transients, of decoherence effects, or of any breaking of the exact boost invariance of the Ernst metric shows that uniformly accelerated black holes do emit an energy flux given by the Doppler-shifted Hawking radiation, in perfect {\it agreement} to what happens for accelerated particles. 
S. Massar and R. Parentani