The wiretapping of telephone conversations is one of the most intense forms of interference with personal life. Such measures can be lawful, particularly for the purpose of uncovering serious crimes, but the mere fact that the wiretapping was conducted with the court's permission does not mean that there is no violation of the right to personal life.
This issue was thoroughly examined by the European Court of Human Rights in the case of Dragojević v. Croatia.
The applicant was suspected of participating in the illegal trafficking of drugs from Latin America to Europe. At the request of the prosecution, the investigating judge authorized the wiretapping of his telephone conversations and the application of other secret surveillance measures in 2007. Subsequently, the duration of these measures was extended several times.
At first glance, everything was done in accordance with the procedures prescribed by law: there was a request from the prosecutor, there was a court decision, and the wiretapping was carried out within the framework of a criminal case.
However, the problem lay in the insufficient reasoning of the court's decision.
The decisions allowing for secret surveillance mainly stated that the investigation "could not be carried out by other means" or that it would be "extremely difficult." However, the court did not present specific facts and reasons that would show why wiretapping was necessary in this particular case and why the same objective could not be achieved by means that interfere less with the individual's rights.
In this case, the ECHR reaffirmed that the wiretapping of telephone conversations constitutes an interference with the right to respect for private life and correspondence guaranteed by Article 8 of the Convention.
In such cases, it is not sufficient to simply provide for the possibility of wiretapping in the law. There must also be real guarantees against arbitrariness.
In particular, wiretapping must be subject to prior and proper judicial control. The court's decision must allow for an understanding of what facts gave rise to reasonable suspicion against the individual, why wiretapping was necessary in this case, why the objective of the investigation could not be achieved by other, less intrusive means, what the scope of the surveillance is, how long it will be applied, and whether the measure used is proportionate to the pursued objective.
The ECHR specifically emphasized that national law also provided for prior judicial control and required a reasoned decision that must demonstrate the necessity and proportionality of the secret measure.
In the ECHR's assessment, the discretion granted to competent authorities in the field of secret surveillance cannot be unlimited. The law and its application must clearly define the scope of that discretion and provide effective guarantees protecting the individual's private life from arbitrary interference.
One of the important features of the case was that the practice established by the higher courts of Croatia allowed for the subsequent supplementation of the initial reasoning for the authorization of wiretapping, even if it was absent or incomplete.
The ECHR found this approach problematic. In the court's view, the essence of judicial control over wiretapping is that its necessity and proportionality must be assessed before the interference is carried out, not after the wiretapping has already been conducted and the data collected. Post-hoc reasoning cannot replace proper prior judicial control.
The ECHR concluded that the procedure for authorizing and overseeing the implementation of wiretapping in this case did not provide sufficient guarantees against arbitrary interference and noted a violation of Article 8 of the Convention.
At the same time, a violation of Article 8 does not automatically imply a violation of the right to a fair trial. The use of evidence obtained through wiretapping is assessed separately by the ECHR in the context of the overall fairness of the criminal proceedings. No violation of Article 6 was found in the Dragojević case.