Turkish police on Tuesday detained 10 people accused of links to the faith-based Gülen movement in an investigation by Ankara prosecutors into alleged activity conducted through Signal, a global encrypted messaging app.
Detention warrants were issued for 13 people, three of whom police were in the process of searching for, the Ankara Chief Public Prosecutor’s Office said. Turkey’s National Intelligence Organization (MİT) and the counterterrorism branch of the Ankara Police Department coordinated the operation.
Turkish President Recep Tayyip Erdoğan has targeted followers of the Gülen movement, inspired by the late Muslim cleric Fethullah Gülen, since corruption investigations in December 2013 implicated him as well as some members of his family and inner circle. He dismissed the probes as a Gülenist conspiracy and designated the movement as a terrorist organization in May 2016, intensifying a sweeping crackdown after a coup attempt in July of the same year that he accused Gülen of orchestrating. The movement denies involvement in the coup attempt or any terrorist activity.
Prosecutors said the 13 were identified during work intended to uncover alleged movement activity conducted through Signal and contended that they were part of the movement’s “current information technology structure.” The wording suggests investigators obtained Signal communications or other information that helped identify the 13 people, but it does not explain whether they accessed message content or how any material was obtained. The statement also does not disclose the alleged messages, the conduct attributed to each person or the criminal provision cited in the warrants.
The state-run Anadolu news agency described Signal as “the organization’s encrypted messaging program,” while the pro-government media claimed a movement Signal network had been deciphered, although the prosecutor’s statement does not say investigators broke the service’s encryption.
Signal is a general-purpose messaging service operated by an independent US nonprofit and used by millions of people around the world, among them journalists, activists, government officials and ordinary users.
The service uses end-to-end encryption, which is designed to prevent Signal itself or anyone intercepting communications in transit from reading their content. Investigators can nevertheless obtain messages from a seized or unlocked phone, a linked computer or another participant’s device without breaking Signal’s encryption. Signal use is not illegal in Turkey, and the statement does not establish whether installing or using the app resulted in the detention orders.
In a 2021 case prosecutors cited Metin Can Yılmaz’s installation of Signal as evidence of alleged movement links, prompting him to file a complaint against Elon Musk because the technology entrepreneur had recommended the app; prosecutors dismissed it on the grounds that using Signal was not a crime. In another Ankara investigation in November 2025 prosecutors issued detention warrants for 19 people after Signal messages were allegedly recovered from the digital devices of a person detained earlier.
The European Court of Human Rights (ECtHR) has faulted Turkey for treating the use of ByLock, another encrypted messaging app, as conclusive proof of terrorist organization membership without assessing the evidence against each defendant.
This article is republished from Turkish Minute.
