A cell phone seized from a senior member of the Gülenist Terror Group (FETÖ) will be used to decipher a list of contacts he had among other executives of the terrorist group.

Mehmet Yıldız (Above), a religion and ethics teacher at a high school in Adana, was fired on Sept. 1, 2016 for membership to FETÖ before being arrested on Sept. 7, 2016 for having downloaded the ByLock messaging app on his phone.

FETÖ, a criminal enterprise founded by fugitive Fetullah Gülen, has been directly implicated in the December 2013 judicial coup attempt and the July 15, 2016 military coup attempt against the democratically elected government of Turkey. With its media and business arms, the terrorist group created significant public clout, which was augmented by infiltration into state institutions, principally the judiciary, police and military. Many of its most senior members fled abroad on the eve or soon after the coup attempt in 2016.

Dating back to the 1960s, FETÖ was the brainchild of Gülen who served as a primary school educated imam before founding the group, which has always acted as a secretive cult.

The 1970s and 1980s were spent consolidating the group, creating the necessary education and financial structure, while slowly infiltrating state institutions. Its schools and prep schools served as the main recruiting ground for the group, which assigned particular degrees and vocations to its members.

Its leadership hierarchy was hidden from the public, apart from Gülen himself. FETÖ, like many terrorist groups, created a structure based on individual cells within various state organizations, like the judiciary, police and military.

Cells of various sizes were each organized around an imam, often an academic or police officer. It was normal practice for FETÖ member generals, prosecutors and judges to receive orders from an academic or teacher. Group hierarchy always trumped civilian hierarchy.

Over the years, FETÖ transformed into a behemoth, with finance, business, education and media arms spread across the globe. It has charter schools in the U.S., mainly used to collect and siphon federal funds into various FETÖ projects, while its schools in the rest of the world are usually used for recruiting.

Gülen is viewed as a sort of messiah by his followers, according to former members.

Yıldız, a high school teacher, was one of the senior imams in the police. The phone seized, according to officials, was specially delivered from the U.S. for his communicative needs. He was able to call other senior FETÖ leaders without any risk of surveillance by local authorities because the phone had a GSM card from a U.S.-based company.

When he was first detained in September 2016, while admitting the phone was his, Yılmaz denied ever using the ByLock app. He also dismissed accusations that he had any links to FETÖ. He was released in March 2017.

However, a month later, police investigations in cooperation with the National Intelligence Organization (MİT) revealed a list of senior imams across the country and that Yılmaz was on the list. An arrest warrant was issued.

Yılmaz was located at a safe house used by FETÖ in Adana on Dec. 27, 2017. It was later found that Yılmaz had frequently changed homes and lived in constant fear of capture since his release.

Reports said the police seized two cellphones in addition to the one mentioned above. His ByLock username was "Sinan," and a four-page list of contacts of senior FETÖ executives was found in his ByLock account.

Once MİT discovered the ByLock app, Yıldız, like many FETÖ members, switched to Eagle.