John Wadham: Security or freedom – take your pick

In the aftermath of last week's events, both politicians and public may well demand drastic measures against the insidious dangers of the new breed of international terrorism. That means there will be growing demands for technology to help us to monitor people around us. That means more CCTV, more passport checks and more demands for identification papers.

In Britain we have got used to more of these security measures than other countries. The extra measures being contemplated in America at the moment, such as tighter airport security and increased CCTV surveillance, are already in place here.

But it is possible that in Britain, too, we will see the tightening up of security yet again – and that will inevitably have repercussions for civil liberties. The predictable calls for identity cards is a case in point. To ensure that police could track a person's whereabouts we would all be obliged to carry cards. Random stops to demand the card would need to be the norm to have any chance of finding a person without one.

However sophisticated the cards, there is every likelihood that more organised groups of terrorists will try to find ways to copy and steal cards in order to create false identities. So the pressure is on to produce the foolproof card. This is particularly the case for passports, using new facial-recognition technology.

The result of all this may well be that we all feel safer. But we will also lose anonymity and privacy. When the Prevention of Terrorism Act was passed in 1974 it was supposed to last for six months. Last year it was put on a permanent footing. Too often a government's easiest answer to demands to do something is to abolish some ancient right in order to show the voters that something is indeed being done.

John Wadham is director of Liberty. Additional research by Heather Tomlinson