ISIS in Iraq executed a woman who operated a brothel.

Answer

America's surrogate, cardboard 'caliph', has murdered innumerable Muslims for no valid reason. Anyone within the ambit of his clutches who refuse to give bay't (offer allegiance) to him is executed. It is not permissible to execute a woman who operates a brothel. It does not matter who committed the killing. They were not justified. The brothel should have been closed down and the woman held in prison until she made Taubah. Prostitution is less than irtidaad. A woman may not be executed for even irtidaad in terms of the Hanafi Math-hab. She has to be detained in jail until she makes Taubah.