A federal appeals court on Tuesday revived a Wikipedia lawsuit that challenges a U.S. National Security Agency program of mass online surveillance, and claims that the government unconstitutionally invades people's privacy rights.

By a 3-0 vote, the 4th U.S. Circuit Court of Appeals in Richmond, Virginia, said the Wikimedia Foundation, which hosts the Wikipedia online encyclopedia, had a legal right to challenge the government's Upstream surveillance program.

The decision could make it easier for people to learn whether authorities have spied on them through Upstream, which involves bulk searches of international communications within the internet's backbone of cables, switches and routers.