Comment on "Probing vortex unbinding via dipole fluctuations"
  We demonstrate that the method suggested by Fertig and Straley [Phys. Rev. B 66, 201402 (2002)] for the identification of different phases in two-dimensional XY models does not allow to make any unambiguous conclusions and make a tentative proposal of another approach to this problem. 
S.E. Korshunov