Mohammed Emwazi known as extremist before he left to join the ISIS jihad . analysts say MI5 's heavy surveillance drove him down due to radicalism . Pressure group Cage said Emwazi was ‘ gentle ’ before being captured by terrorists . But Prof Glees says spooking people like Emwazi is ' absolutely necessary ' The only people who gain from criticising themselves are terrorists , he claims .
Mohammed Emwazi known as extremist before he left to join the ISIS jihad . Critics say MI5 's heavy surveillance drove Emwazi down path to radicalism . Pressure group Cage said Emwazi was ‘ gentle ’ before being probed by MI5 . But Prof Glees says spooking people like Emwazi is 'absolutely necessary ' The only people who gain from criticising MI5 are terrorists , he claims .