Civil liberties make it harder for governments to govern. Governments will use any excuse to curtail freedoms. It is said that restrictions on freedoms (ie Patriot Act) were already drawn up before 911 and 911 was merely the excuse to implement them.

There is little accountability when it comes to the effectiveness of specific controls in combating terrorism. The government will say it helps prevent but there is no audit, no figures, no details to proof this. Everything is shrouded in the national secrets laws.

My view is modest controls (ie metal detectors) will prevent most of the amateur terrorist attempts like airplane bombing or highjacking but are taken too far. The controls do little against well financed professional terrorists especially when they can easily switch targets to public places like malls, buses etc. The most effective precaution is intelligence from infiltrators.

In my view any proposed control that curtails civil liberties must present a sound legal argument in court that it would be of significant value and then should only be authorised for a limited period after which evidence must be presented as to its effectiveness if the control is to be continued.