This is actually my second post with this title.
During this Week-End I have read Spook Country by William Gibson and one of the characters says something about terrorism which is so true but people tend to forget:
Are you really so scared of terrorists that you'll dismantle the structures that made America what it is?
If you are, you let the terrorist win. Because that is exactly, specifically, his goal, his only goal: to frighten you into surrending the rule of law. That's why they call him 'terrorist'. He uses terrifying threats to induce you to degrade your own society.