David Cameron's had a rough ride on both sides of the Atlantic with his plans to ban encrypted communications.

Reactions included "colossally stupid", "idiotic" and "technologically illiterate" from former White House cyber officials to people in the digital technology industry.

But there is another reason to be worried about the Government's attempt to assume even more anti-terror powers - the potential for their abuse.

Justifying his controversial proposals, the Prime Minister insisted to Sky News: "We don't want to interfere with the privacy and civil liberties of our citizens."

Yet his Government is currently defending the use of existing anti-terror legislation to do just that.

There was outrage earlier this year when British police were revealed to have used laws designed to target terrorists to spy on journalists instead.

Journalists and press freedom advocates warn the secret surveillance is already having a chilling impact on whistle-blowers.

Ordinary people who want to expose wrongdoing to journalists will think twice if they believe the police have placed the press under surveillance.

The first force to be exposed secretly using anti-terror laws to spy on journalists was London's Met.

The Regulation of Investigatory Powers Act was passed to protect national security and stop terrorists.

The London police used it to spy on Sun political editor Tom Newton Dunn, not to prevent a terrorist outrage, but instead to find his police sources during the Andrew Mitchell "plebgate" affair .

Police were able to view his private mobile phone records without his knowledge because of a piece of legislation that had been justified originally only to protect national security.

Since then the UK Press Gazette has revealed the same law is being used by other police forces to spy on more journalists.

Home Secretary Theresa May has listened to all the outrage and drawn up legislation that will effectively legalise the right of police to continue spying on journalists.

The proposal rides roughshod over the decades-old principle that it is in the public interest for journalists' sources to be protected.

Journalist surveillance need only be approved by a senior police officer, not a judge.

The National Union of Journalists has warned that Theresa May's proposal "denies journalists an opportunity to defend the confidentiality of their sources, and information that deserves to be in the public domain won't see the light of day as a consequence".

The freedom of ordinary citizens and the press to expose and reveal wrongdoing by government and others is a cherished liberty.

In America it is enshrined in the constitution.

Secret police surveillance of the press for minor crimes is common in less free societies.

In Britain it has already begun.

In the light of all that, the Prime Minister's pledge that new anti-terror laws will not interfere with civil liberties and freedoms rings hollow.

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