Turkish authorities have detained 160 people over alleged links to the faith-based Gülen movement in operations across 39 provinces over the past two weeks, Interior Minister Ali Yerlikaya said on Wednesday, a move announced on the same day of a major ruling by the European Court of Human Rights (ECtHR) that faulted Türkiye over convictions based on the use of the encrypted messaging app ByLock.
Yerlikaya said the detentions took place over the last two weeks across 39 provinces, including Ankara, Istanbul, Izmir and Antalya. He added that 90 suspects were arrested pending trial and 52 were released under judicial supervision, while procedures were continuing for the remaining detainees.
The minister said the suspects were accused of activities linked to the Gülen movement, including alleged contact through pay phones and alleged use of ByLock, an application Turkish prosecutors and courts have treated as a key indicator of organisational membership in thousands of cases since the failed coup attempt of July 15, 2016.
The announcement came as the ECtHR, in three Committee judgments released on Dec. 16, found violations of the European Convention on Human Rights in 2,420 applications arising from convictions for terrorism-related offences where domestic courts adopted a categorical approach to ByLock—treating the mere use of the app as sufficient, in principle, to convict someone of membership in an armed terrorist organisation.
In the grouped cases—Bozyokuş and Others v. Türkiye, Karslı and Others v. Türkiye, and Seyhan and Others v. Türkiye—the court held unanimously that there had been a violation of Article 7 (no punishment without law) and/or Article 6 § 1 (right to a fair trial). The judgments are final, and the ECtHR said reopening domestic proceedings would, in principle, constitute the most appropriate form of redress available under Turkish law.
The ECtHR framed the issue as systemic, building on its 2023 Grand Chamber ruling in Yüksel Yalçınkaya v. Türkiye and a subsequent Chamber judgment in Demirhan and Others v. Türkiye, warning that Türkiye’s uniform approach to ByLock evidence risked arbitrary prosecution and punishment and unduly restricted defence rights.
Türkiye designates the Gülen movement a terrorist organisation and blames it for the 2016 coup attempt. President Recep Tayyip Erdoğan began targeting the movement’s followers more aggressively after corruption investigations in December 2013 implicated members of his inner circle—allegations his government dismissed as a conspiracy—then intensified the crackdown after 2016.
Official Turkish figures show the scope of the post-coup legal campaign remains vast. Justice Minister Yılmaz Tunç said in July 2025 that 58,000 suspects were still under investigation, 24,000 cases were ongoing, and 11,085 convicted people were in prison, while also stating that 126,796 conviction decisions had been issued for civilians.
The juxtaposition of the latest detentions with the ECtHR’s ByLock decisions is likely to intensify scrutiny of how Turkish prosecutors and courts interpret “digital evidence” and whether domestic practice will shift in response to Strasbourg’s demand for case-by-case assessment rather than automatic guilt by association.
