The revelation in the Guardian by the American whistleblower, Edward Snowden, that the US Government is in some way monitoring the internet usage of its citizens has caused a storm of protest.

Headlines suggested that the surveillance society envisaged by George Orwell's novel Nineteen Eighty-Four had finally come to pass and that nobody's privacy was safe in the internet age.

The truth, as the Foreign Secretary explained to the House of Commons, is rather less sensational.  William Hague insisted that intercepting the content of any individual's communications in the UK requires a warrant signed personally by him or the Home Secretary.

He went on to say that a "partial and potentially misleading picture" is created by leaks of this kind, which can give rise to public concern and make the job of the security service even more challenging.

In the Commons I reminded MPs that our country's national security has relied for centuries on intercepting communications.  The Spanish Armada was said to have been averted as much by the pen of Queen Elizabeth's spymaster, Sir Francis Walsingham, as by the Royal Navy.

What has changed is the nature of the communications being intercepted.  I made these arguments in the Times in the week after Drummer Lee Rigby's murder on the streets of Woolwich.

Communications data is used in 95 per cent of all serious and organised crime investigations.  It has also played a significant role in every major Security Service counter-terrorist operation over the last decade.

However, there is now a growing capability gap for our police and intelligence agencies in tracking criminal activity, because unlike landlines, communications records are not kept on social media like Facebook.

Of course, civil liberties must be protected, but that means putting in place the right safeguards, not dismissing contemporary realities.  Our laws have always sought to achieve a proper balance between liberty and security; neither can trump the other.

Sir Robert Peel, faced strident opposition to his plans for creating the Metropolitan Police Force.  Peel finally prevailed against those who thought his "blue devils" were an attack on freedom.  "Liberty", he said, "does not consist in having your home robbed by organised gangs of thieves."

Law enforcement agencies haven't the slightest interest in the e-mails or web-browsing habits of law-abiding citizens.  But they do need the ability, with proper authorisation, to monitor the communications of the most dangerous criminals.

Christopher N Howarth