As is common after a violent tragedy, a great deal of electrons are being annoyed by people who are calling for prohibitions. Some want to prohibit firearms, ammunition, and body armor while others want to prohibit members of an entire religion from crossing the imaginary line that separates the United States from the rest of the world. All of this finger pointing is being done under the guise of security but the truth is that any security system that depends on an attacker acting in a certain way is doomed to fail.

Prohibitions don't eliminate or even curtail the threat they're aimed at. In fact the opposite is true. The iron law of prohibition, a term coined in regards to prohibitions on drugs, states that the potency of drugs increases as law enforcement efforts against drugs increases. It applies to every form of prohibition though. Prohibitions against firearms just encourages the development of more easily manufactured and concealable firearms just as the prohibition against religious beliefs encourages those beliefs to be practices in secrecy.

When you rely on a prohibition for security you're really relying on your potential attackers to act in a specific way. In the case of firearm prohibitions you're relying on your potential attackers to abide by the prohibition and not use firearms. In the case of prohibiting members of a specific religion from entering a country you're relying on potential attacks to truthfully reveal what religion they are a member of.