On June 23, 2026, the European Court of Human Rights delivered a landmark judgment that reinforces and expands its Yalçınkaya jurisprudence (Grand Chamber, 2023). The Court condemned Türkiye in a large-scale case involving more than 260 applicants, including Mr. Hüseyin Özyurt, who was successfully represented before the Court by Mr. Grégory Thuan Dit Dieudonné.

The Strasbourg Court found a structural and systemic violation of Article 6 § 1 of the ECHR (right to a fair trial). Domestic courts had adopted an automatic approach, treating the mere use of the encrypted application “ByLock” as conclusive evidence of membership in a terrorist organization, failing to provide procedural safeguards or a meaningful opportunity to challenge the evidence.

Key Takeaway: The judgment highlights the generalized nature of this judicial practice and, through the defense of Mr. Thuan Dit Dieudonné, paves the way for the reopening of domestic criminal proceedings in Türkiye as the primary form of redress under Article 41 ECHR.