Let's state the facts: There are biological, chemical, and nuclear weapons that can kill millions of people today owned by state organizations. Some of these states have questionable long-term motives whether driven by power or resources.

There are stateless organizations that would use those weapons in a moment's notice against the entire population of the United States.

What you are suggesting is that there is no current evidence of weapons of mass destruction being moved or the knowledge and capital required to make such weapons being from a state to a state-less organization. I disagree:

Number of terrorist groups that have demonstrated interest in acquiring a nuclear weapon: 4

Al Qaeda, Chechnya-based separatists, Lashkar-e-Taiba, and Aum Shinrikyo

Number of terrorist groups that may be capable of acquiring and using nuclear weapons: 5

Al Qaeda, North Caucasus-based separatists, Lashkar-e-Tayyib, Hezbollah, Taliban

Number of known groups that have attempted to buy nuclear material on the black market: 2

Aum Shinrikyo and Al Qaeda

Even if so, there is evidence of weapons of such scale in questionable states such as Syria. In addition there is evidence of weapons transfer, albeit not chemical, biological, or nuclear, to stateless organizations.

Millions of people do not have to die to have a substantial impact on a nation. For you what is that number? Is it in a nominal amount of deaths that reach above the amount of second hand smoke or car crashes?

Regardless, from a perspective of economic cost giving up the civil liberty of driving as a result of deaths is not parallel to giving up the civil liberty of someone checking your phone records.

For now you will not be willing to give up your civil liberty since the probability of you being hit by a terrorist attack is low ( I would be willing to wager you to do not live in major metropolitan city). Given the current pace it is a function of time before a stateless organization increases its death count. At that point you will be willing to give up some of your civil liberties.