> You can't protect against an opponent who's motivated to learn the inherent vulnerabilities of our systems, many of which can't be protected against due to the laws of physics and practicality

Ah yes, the insidious opponent who learns the inherent vulnerability of ... huge crowds gathering before hand baggage screenings and TSA patdowns.

And these crowds are only there only due to a permanent immovable physical fixture of ... completely artificial barriers that fail to prevent anything 90-95% of the time.