The union representing German journalists advised its members on Thursday to stop using Google and Yahoo because of reported snooping by U.S. and British intelligence. The Deutscher Journalisten-verband (DJV) advised journalists not to use the search and e-mail services from Google and Yahoo for their inverstigations and communications, "until further notice."

The Washington Post reported on Wednesday that the NSA had tapped directly into communications links used by Google and Yahoo to move large amounts of email and other user information between overseas data centers. It said the program was operated jointly with GCHQ.

DJV national chairman Michael Konken said that the search queries made journalists are just as confidential as the contact details of their sources and the contents of their communication with them.

He cited "scandalous" reports of interception of both companies' web traffic by the U.S. National Security Agency (NSA) and Britain's GCHQ. He added that there are other search engines and email providers that journalists should use.

Google's chief legal officer said it was 'outraged' at the apparent interception of data from its private fiber networks. The company declined to comment on the German union move. Yahoo said it had strict security in place at its data centers and had not given access to the NSA or other agencies.

DJV's move follows last week's announcement by the German government that it had evidence that Chancellor Angela Merkel's mobile phone had been monitored by U.S. intelligence.

Earlier this month, Deutsche Telekom also said it wanted German companies to cooperate to shield local internet traffic from foreign intelligence services.