Citation by one national court of another state’s jurisprudence or legislation has attracted much attention recently, especially in relation to the interpretation and application of constitutional and international human rights norms. Commentators document these practices, judges extol or deride them, and academics theorise about them. A commonly shared assumption is that the comparative undertakings are accurate and systematic, if superficial. Tracking judgments from the European Court of Human Rights and the Supreme Court of Canada across a series of cases dealing with non-citizens and national security reveals that courts not only circulate practices and legal arguments between jurisdictions, they also circulate – perhaps inadvertently – misrepresentations of practices, and remain strategically deaf to dissonant arguments. Scholarly accounts of transjudicial communication that claim to document the emergence of a systematic pattern of judicial behaviour across jurisdictions should take these practices seriously and avoid the temptation to dismiss them as mere aberrations.