Who are the terrorists talking to? We must know.
To claim that letting the security agencies find out who terrorist suspects have been talking to is as evil as hacking down an unarmed soldier is a sign of missing judgment.
The call, after the murder of Drummer Lee Rigby, to revive a Government Bill that would allow the authorities to monitor the online activity of possible terrorists has been met with a paranoid libertarianism that denies any sense of proportion.
The familiar argument is that the excessive infringement of civil liberties becomes a "recruiting sergeant" for terrorists. This may be true in the case of measures such as long periods of detention without trial. But using new technology to intercept terrorist plots doesn't recruit terrorists: it jails them. The actual recruiting sergeants are the preachers of hate, some of whom we cannot remove from this country because of the same failure to distinguish rights from wrongs.
In Theresa May's foreword to the draft Data Communications Bill, the Home Secretary warned that without action terrorists will not be caught and "no responsible government could allow such a situation to develop unaddressed". In which case, Nick Clegg is being irresponsible in preventing the Government from bringing the measure forward.
We cannot ever know whether allowing law enforcement agencies to access communications data would have prevented the murder of Lee Rigby but the former independent reviewer of terrorism legislation, the Liberal Democrat peer Lord Carlile of Berriew, swiftly criticised Mr Clegg for having blocked the proposals this year. Parliament's cross-party Intelligence & Security Committee has also accepted that "there is a serious problem that requires action".
The web's powerful freedom cannot be inviolate when it becomes harmful - whether in allowing children to see pornography or terrorists to plot murder. Technological advance presents new opportunities to fight crime, but also new means to commit it.
Law enforcement agencies rely on the communications records of suspects to fight serious crime, though they can only access the content - as opposed to the fact of contact with someone - with a warrant issued by the Home Secretary. But where once communication was by landline, now a quarter of the data that the authorities need cannot be obtained because it is in the form of e-mails or messages on social media, and the proportion is set to rise sharply. That is why it is necessary for the Government to require internet companies to retain data such as e-mails for a year, just as telephone records are retained now.
Yet this proposal was branded a "snooper's charter". Indeed, much of the criticism has been near-hysterical. Some claimed that the measures would be used to enforce traffic offences or illegal music downloads. The Editor of The Spectator suggested that the main purpose of the Bill was "about giving espionage powers to the taxman". The Director of Liberty asserted that the measure would result in "blanket surveillance of the entire population". A Lib Dem MP even said that "we are all suspects under this Bill".
All of these claims are absurd. The laws currently controlling access to communications data would remain. It is only allowed for specified purposes and must be proportionate; 99 per cent of authorisations are given to the police and intelligence agencies, rather than other bodies. If there are concerns about the breadth of these purposes, they can be addressed by focusing the legislation more tightly.
But the paranoia that some display about state intrusion makes such rational consideration impossible. Communications data isn't their only demon. Other crime-fighting tools such as CCTV cameras and the DNA database are seen as threats, too. This reflex opposition to intrusion trivialises - often to the point of being dismissive - the threat of crime. To believe that the harm caused to you by having a camera on a street corner equates to the harm caused by a mugging is to lose proper perspective. Such attitudes blind critics to the benefits of new technology, even though thousands of cases are solved using it, serious crimes are prevented and victims are spared.
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.
An earlier home secretary, Sir Robert Peel, faced strident opposition, including from within his own party, to his plans to create 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."
That is a truth that some misguided disciples of civil liberties might remember today.