Game Theory and Immunology have been used in previous posts to offer a perspective on the challenges our society faces with competing interests on security and safety. The paper entitled Passive Versus Aggressive Strategies: A Game Theoretic Analysis of Military and Immune Defense illustrates how theorists are studying biological systems to inform us on the optimal defense strategies against terrorism; the very chicken-to-the-egg that spawns the debate over the NSA warehousing of 'public' (and arguably private) phone record data.
Continuing with this theme and informed by the adage "[T]here's nothing new under the sun", it's illuminating to study how a defense mechanism honed over billions of years of Evolution has developed a time-tested 'best practice' to reconcile the public/private dynamics.
Consider the Blood-Brain-Barrier (BBB). A Socratic would ask, 'Why does the brain need a barrier from the rest of the body...isn't it part of the whole?' Another question would be, 'If the structure of a barrier has so many benefits to the brain, why is it not extended to the whole body?' Immunologically and game-theoretically speaking, the dynamics at 'play' are trade-offs balancing the benefits and costs of complexity. Brains are very 'expensive' organs from an energy usage perspective, but they also provide tremendous Evolutionary advantage.
Through 'error-then-trial' and in-keeping with the universal that "everything is the way it is because it got that way", the immune system's BBB settled on a limited, highly restrictive ('private') area relative to the rest of the body. It takes more biological effort to support the complexity of this 'private' area, but it also has its rewards. Scaled-up to the dynamics of humans interacting in society, privacy has a utility, maximizing liberty and minimizing tyranny, that comes at a high cost when the society itself is under attack by the forces of terrorism. The book 'The Science of Good and Evil: Why People Cheat, Gossip, Care, Share and Follow the Golden Rule' explores competing interests at the individual, tribal and intra-tribal levels along with the strategies that arise from these interactions.
The NSA's mission to provide intelligence for our national defense/'immune' system is made more complex by burdening it with the restrictions of 'privacy'. Contrary to the chairman of the House Permanent Select Committee on Intelligence's arguments, we can allocate resources to service providers to keep customer information private (relative to the government) behind a barrier; yet readily accessible (à la NexisLexis-style business-to-business access) when authorized by the FISA Court. Like the immune system's Blood-Brain-Barrier, some costs are worth paying for the benefits when developing an optimal defense strategy that has to take into account competing interests.