Diversity destroys social trust, even among people who are naturally high trust. In the comments is a good story about how low trust leads to more low trust. In order to avoid being called racist, we have anarcho-tyranny: the government and businesses treat people of all races equally. There is some truth to the argument that treating people like criminals is counterproductive, but like all things it is a continuum. When one group is heavily responsible for theft or terrorism, keeping a close eye on them may increase some friction with the group, but lower overall theft/terrorism. If instead everyone is profiled, the result is widespread loss of trust and a much smaller reduction in theft/terrorism due to resources spread thin. The resulting loss of trust undermines support for the effort as well, and may increase the risk of backlash. Take the TSA, all it does is create hatred for the government. It fails to do anything of substance to reduce terrorism, while greatly increasing anger and lowering trust.
No one leaves the door unlocked anymore
Charlie Rose - From Radar in 2007:
3 hours ago