PARIS/FRANKFURT - As a diplomatic row rages between the United States and Europe over spying accusations, state-backed Deutsche Telekom wants German communications companies to cooperate to shield local internet traffic from foreign intelligence services.
Yet the nascent effort, which took on new urgency after Germany said on Wednesday that it had evidence that Chancellor Angela Merkel's mobile phone had been monitored, faces an uphill battle if it is to be more than a marketing gimmick.
It would not work when Germans surf on websites hosted on servers abroad, such as social network Facebook or search engine Google, according to interviews with six telecom and internet experts. Deutsche Telekom could also have trouble getting rival broadband groups on board because they are wary of sharing network information.
More fundamentally, the initiative runs counter to how the Internet works today - global traffic is passed from network to network under free or paid-for agreements with no thought for national borders.
If more countries wall themselves off, it could lead to a troubling "Balkanisation" of the Internet, crippling the openness and efficiency that have made the web a source of economic growth, said Dan Kaminsky, a US security researcher.
Controls over internet traffic are more commonly seen in countries such as China and Iran where governments seek to limit the content their people can access by erecting firewalls and blocking Facebook and Twitter.
"It is internationally without precedent that the internet traffic of a developed country bypasses the servers of another country," said Torsten Gerpott, a professor of business and telecoms at the University of Duisburg-Essen.
"The push of Deutsche Telekom is laudable, but it's also a public relations move."
Deutsche Telekom, which is 32 per cent owned by the government, has received backing for its project from the telecoms regulator for potentially giving customers more options.
In August, the company also launched a service dubbed "E-mail made in Germany" that encrypts email and sends traffic exclusively through its domestic servers.