The European Court of Justice (ECJ) ruled that the practice of Jehovah’s Witnesses collecting personal information as it’s converters go door-to-door to preach is illegal. According to the court ruling, they are effectively compiling a personal data register, which should comply with EU data protection regulations (the GDPR). Jehovah’s Witnesses’ practice was under scrutiny since 2013 in Finland, where the Supreme Administrative Court asked the ECJ for an opinion last year. The ECJ preliminary ruling is expected to be followed by Finland’s Supreme Administrative Court’s official ruling.