A bicyclist wearing a face mask is seen near the Brandenburger Gate in Berlin, capital of Germany, March 28, 2020. (Photo by Binh Truong/Xinhua)

Germany's Federal Intelligence Service (BND) violated the constitution by spying on internet data from foreigners abroad, the nation's top court ruled Tuesday in a victory for overseas journalists who brought the case.

The BND agency's surveillance violates "the fundamental right to privacy of telecommunications" and freedom of the press, judges at the Constitutional Court in Karlsruhe said in their verdict.

But given the "great importance" of foreign surveillance to German security, the court gave the BND until the end of 2021 to change its practices and comply with the law.

The ruling marked the first time the Constitutional Court clearly stated that the BND must respect fundamental rights accorded to the Germany's Basic Law constitution even when operating abroad.

German intelligence services are already not allowed to monitor the internet traffic of Germans in such a vast way.

The case was brought by journalists and civil society groups who were outraged after the BND was granted sweeping new powers to carry out "strategic telecommunications surveillance" under amended legislation in 2016.

This allowed the BND to tap into internet traffic from non-Germans abroad, often through monitoring the use of keywords, phone numbers or email addresses, and to share this information with other secret services.

One of the plaintiffs, Reporters Without Borders (RSF), argued that this allowed the agency to spy on journalists "almost without restrictions."

"The journalists' mission of monitoring the activities of the state is rendered ineffective if these states are listening in on their conversations while they do their research," said RSF on its website.

The mass surveillance also deterred sources from contacting reporters covering topics such as corruption, tax fraud and human rights abuses, it argued.

AFP