In the earlier case, Roman Zakharov v. Russia, a publisher in St. Petersburg challenged laws allowing the government to intercept mobile phone conversations without a judicial order. The more recent Szabó and Vissy v. Hungary challenged anti-terrorism laws allowing the Hungarian police to search electronic communications, mail and homes without judicial approval.
In Zakharov, … The Court found that a government may only intercept telephone communications where the body authorizing the surveillance has confirmed that there is a “reasonable suspicion” of wrongdoing on the part of “the person concerned.” This language, along with the Court’s statement that a surveillance authorization “must clearly identify a specific person … or a single set of premises” as the subject of the monitoring, seemed to set the stage for a ruling that UK-style society-wide surveillance programs such as Tempora are illegal under the ECHR.
The Court in Szabó and Vissy considered whether the challenged Hungarian laws provide “adequate and effective guarantees against abuse.” The answer was no: the phrase “strictly necessary in a democratic society,” the Court explained for the first time, means not only that a surveillance measure must be strictly necessary for “safeguarding the democratic institutions” at a general level, but must also be “strictly necessary … for the obtaining of vital intelligence in an individual operation.” Crucially, the Court added that the Hungarian authorities must therefore interpret a law allowing surveillance authorizations to apply to “a range of persons”—which, as the Court observed, could potentially include everyone in Hungary—very narrowly. According to the Court, the body authorizing the surveillance must “verify whether sufficient reasons for intercepting a specific individual’s communications exist in each case.”
For more information, see: Did the European Court of Human Rights Just Outlaw “Massive Monitoring of Communications” in Europe? – CDT