Some critics have complained about the treatment of minority Alevi and Kurdish groups, and of some imprisoned journalists.[1][3][8] As of March 2013, a "mounting number of Turkish lawyers, politicians, journalists" have been imprisoned, in what journalist Dexter Filkins has called "an increasingly harsh campaign to crush domestic opposition".[9] Among the imprisoned are a constitutional law professor (Ragip Zarakolu), a prize-winning investigative journalist (Ahmet Şık), a noted free-speech activist (Nedim Sener),[8]