One year after the Snowden revelations, Vodafone admitted today that several governments around the world have placed wires within its telecoms infrastructure in order to listen to phone calls made over its network.
The telecoms giant said it was revealing the information in a bid to push back against increasingly widespread use of phone and broadband networks to spy on citizens.
Security agencies across the world, particularly those in the US and the UK, have faced greater scrutiny since Edward Snowden, a former contractor with the US National Security Agency (NSA), disclosed the extent of government surveillance to newspapers.
Outlining the extent of the surveillance acorss its own network, Vodafone published a 40,000 word Law Enforcement Disclosure Report this morning.
The company, which operates in 29 countries and is the world's second largest mobile phone operator, said that, while many governments require legal notices to tap into its network and listen to customer communications, some do not.
Vodafone was unable to specify which countries have access to its network because it's illegal in several of the countries Vodafone operates in to disclose any information related to wiretapping or interception of the content of phone calls and messages including whether such capabilities exist.
The report states that wires, or pipes, have been connected directly to Vodafone's networks and those of other telcos, allowing government agencies to listen to or record live conversations and even track the location of a customer.
The Guardian cites industry sources who say these wires or pipes are locked in a room within a network's central data centre or in one of its local exchanges. They add that staff working in that locked room can be employed by the telecoms company while possessing state security clearance, which means they are usually unable to discuss specific aspects of their work with the rest of the company.
Vodafone said all employees must follow its code of conduct, but secrecy means that it cannot always guarantee that they do so.
In the report, Vodafone calls on governments to amend legislation so eavesdropping can only take place on legal grounds.
Specifically it wants direct-access pipes to be disconnected and for agencies to have to gain warrants to carry out any surveillance, to discourage them from gaining direct access to a communications network with a legal mandate.
Stephen Deadman, Vodafone's group privacy officer, told The Guardian: "We are making a call to end direct access as a means of government agencies obtaining people's communication data.
"Without an official warrant, there is no external visibility. If we receive a demand we can push back against the agency. The fact that a government has to issue a piece of paper is an important constraint on how powers are used."
Mr Deadman added the use of direct-access pipes in the UK would be illegal because agencies have to obtain a warrant to get information.
The report breaks down lawful intercept requests and communications data requests for the 29 countries in which Vodafone operates for the period 1 April 2013 to 31 March 2014.
The UK government made 2,760 interception requests and 514,608 communications data requests to all mobile phone operators in 2013.
By comparison, Italy made 139,962 interception requests in total and 605,601 communications requests to Vodafone alone. In the US, Verizon said it received 321,545 requests for customer information.
Some of the figures are being disclosed by Vodafone for the first time, including those for Spain and Tanzania.
Several countries refused to reveal the number of requests they made, including Egypt, India, Qatar, Romania, South Africa and Turkey.
Mr Deadman said: 'We need to debate how we are balancing the needs of law enforcement with the fundamental rights and freedoms of the citizens.'
Shami Chakrabarti, director of human rights campaign group Liberty, said: "For governments to access phone calls at the flick of a switch is unprecedented and terrifying.
"Snowden revealed the internet was already treated as fair game. Bluster that all is well is wearing pretty thin - our analogue laws need a digital overhaul."