The TSA is security theater and is inefficient and ineffective in my opinion.

http://www.sciencedirect.com/science/article/pii/S0969699713001270

Conclusion:

"The risk and cost-benefit decision framework described herein illustrates the key concepts and data requirements. This provides a starting point for this type of risk analysis – and to flesh out some of the issues, including data requirements becoming more challenging as the systems model increases in detail and complexity. Our analysis considered each security measure in isolation, whereas policy options might prefer a mix of security measures. In this case, security measures may also not be perfectly substitutional; for example, removing one layer of security may alter the systems model and/or risk reduction of other layers of security. A more detailed and comprehensive study is required to properly model the complex interactions and interdependencies in airport security.

The protection of airport terminals and associated facilities such as car parks at LAX from terrorist attack was used to illustrate the cost-effectiveness of protective and counter-terrorism measures. This analysis considered threat likelihood, cost of security measures, and random variability of hazard likelihood, risk reduction and losses to compare the costs and benefits of security measures to decide the optimal security measures to airports. Monte-Carlo simulation methods were used to propagate hazard likelihood, risk reduction and loss uncertainties in the calculation of net present value and benefit-to-cost ratio that also allows probability of cost-effectiveness to be calculated.

It was found that attack probabilities had to be much higher than currently observed rates of attack to justify protective measures. This was the general result even though the analysis was substantially biased toward coming to the opposite conclusion. Thus, we assumed a terrorist attack would inflict considerable direct and indirect damage, that attacks would only target large airports thereby exaggerating their likelihood per target because the many smaller airports were not included in the target count, and were very generous in our estimates about how much the security measures would reduce risk. We also underestimated the costs of the security measures by ignoring any costs entailed in inconveniencing travellers or deterring them from flying.

In fact, it may be worthwhile to consider whether airports are actually very attractive terrorist targets. If the goal of the terrorist is to kill people and inflict physical damage, there are many other places to detonate a bomb or undertake an armed attack. In addition, although the blowing up of an airliner may have considerable negative consequences for the airline and travel industry, an isolated attack at an airport is unlikely to be anywhere near as damaging. Moreover, if the analysis suggests that enhancement of airport security is highly questionable, it may well be time to consider if many of the security arrangements already in place to protect airports are excessive."