A recent piece in the BBC seeks to shed light on the true face of the Gülen Movement:
The scale of the clampdown has drawn criticism from Western governments.
But to grasp what is happening requires an understanding of the Gulen movement: a man whose followers have spread through Turkey’s institutions for the past four decades.
Fethullah Gulen emerged in the 1960s as an Islamic preacher within a constitutionally secular Turkey.
His advocates call him a guru of moderate Islam tinged with humanitarianism, delivering his ideology through a network of high-achieving schools in Turkey and about 140 countries.
Critics say he has built a dangerous cult that has infiltrated all corners of the Turkish state – a fifth column that has shown its true colours in this latest coup attempt.
Members of his movement were embedded until recently within virtually every institution.
A grainy video of the cleric emerged in 1999 apparently calling on his followers to “move within the arteries of the system, without anyone noticing your existence, until you reach all the power centres… You must wait until such time as you have got all the state power”.
Mr Gulen, who has lived in self-imposed exile in the US since 1999, says his words were manipulated.
Some of those who have reported on the shadowy network over the years have faced lawsuits, such as the journalist Ismail Saymaz.
“The Gulen structure aims to surround the state from within and take over”, he tells me.
“They’re not armed militants but cloak themselves as judges, teachers, police, MPs and businessmen.