The killing of an Iranian activist in Canada has exposed bitter divisions within the diaspora over the Iran war. Several activists say they have received threats that led them to notify the police and change their routines. Many of the threats appear to be coming from supporters of an exiled crown prince who supports the war and hopes to return once the Islamic republic is toppled. Activists who oppose the war or the crown prince say they have received threats from his supporters. Allies of the crown prince deny he's involved and accuse Iran's government of masquerading as activists to sow divisions among its opponents abroad.