The notion that terrorists could mount attacks at anytime against free people must be rejected. That free people should be forced to curtail their liberties under a constant, pestering and fearful threat of violence, is preposterous.
Not that conditions are not conducive to these threats - they are in many jurisdictions and locals, but they must be eliminated, so that the free could remain free.
Therefore, decisive action against terror is merited from Paris, to New York, to Ottawa, to London, to Amsterdam, to Berlin, to Brussels and beyond. And to this end, should personal liberty and privacy become more scrutinized in the short-run to effect long- term freedom, then such action must be deemed necessary and be narrowly utilized toward the overall protection of the state.
So in essence, each and every free man and free woman should not mind yielding minimal intrusion of personal privacy to regain national security and personal freedom and safety. And once ill-intended wolves cowering among the free to inflict harm are weeded out and expunged, then mechanisms in place to return full liberty and privacy to the free, must return full rights to the free people.