The things you point out are reasonable. But I think you slightly presuppose the legitimacy of the surveillance regime. Pick a government at random from around

The things you point out are reasonable. But I think you slightly presuppose the legitimacy of the surveillance regime. Pick a government at random from around the world. Give it surveillance technology that is not 100% accurate, and there will be many, many cases where the officials use the imperfect data on the basis of seemingly reasonable fears and suspicions to act without due process and without much guidance from the rule of law. When your job is to prevent catastrophic events, you will be inclined to trust any instrument you have at your disposal, even if it is not completely trustworthy. This is why surveillance powers (or any powers that make it easy to diagnose various forms of thought crime (e.g. premeditation) should be avoided, since they lead to over-confidence on the part of law enforcement and apologies when they lead to innocent lives being ruined. The same "reasonableness" criteria can be used to justify torturing someone who seemingly knows information that could save lives but refuses to reveal it. One of the main benefits of putting process and institutional structure behind law enforcement is to take the emotion out of it and avoid one person deeming something reasonable based on a narrow context that really is not.