Bavaria's constitution protection law is partly unconstitutional and has to be restricted in numerous points.
The Federal Constitutional Court announced this judgment in Karlsruhe on Tuesday (AZ: 1 BvR 1619/17).
The law came into force on August 1, 2016.
It gave the Bavarian Office for the Protection of the Constitution expanded powers, including acoustic home surveillance, online searches and the use of undercover investigators and informants.
Among other things, this was intended to counteract the threat of Islamist terrorism, according to the reasoning.
The civil rights organization "Society for Freedom Rights" coordinated the constitutional complaints against the Bavarian law.
The lawsuit was largely successful.
Bavaria has until July 31, 2023 to remedy the violations of fundamental rights.
Until then, the law can only be applied under certain conditions.