Two lawyers won their case against the Hungarian state concerning legislation on secret surveillance.
The Hungarian government must now obtain judicial warrants for surveillance activities.
The decision by the European Court of Human Rights may be of interest to the whole of Europe.
The complaint submitted by HCLU's executive director and one of its lawyers concerned whether it is sufficient to obtain the permission of a member of the government - a minister - for the authorization of secret surveillance with national security purposes, or if it is necessary to have an independent - ideally judicial - control over surveillance activities.
As potential subjects of surveillance, the applicants claimed that their rights to privacy are violated if the interception is not accompanied by a control mechanism that is independent from the government and surveillance-gathering parties.
This is especially true because, given the secret nature of this type of surveillance, concerned persons are usually unaware of the fact that they are being watched, and are therefore unable to enforce their rights protecting them from such activities.
The same legislation was found constitutional by the Hungarian Constitutional Court in 2013, but now the European Court of Human Rights has ruled that it is incompatible with the Convention on Human Rights.
Instead of mass, indiscriminate data gathering, the court's decision means that Hungarian authorities must obtain a judicial warrant to collect data on a case-by-case basis.
A ruling for the rest of Europe
The judgment has all the more weight since the decision was clearly not influenced by the terror threat in Europe, reinforcing the concept that judicial rulings should set the standards for government behavior, with only limited exceptions being allowed in extraordinary circumstances.
The Strasbourg ruling, as a consequence of which the Hungarian Parliament must reform its act on surveillance for national security purposes, may affect relevant practices in all European countries.