In 2013 I commented elsewhere on this story about detecting concealed weapons in public spaces. I regret that I did not document the specific cases of government and law enforcement overreach to which I alluded*. Nonetheless, the prime point remains valid.
*I believe the Canton case was of the patrolman who acted irrationally abusively toward a CCW holder. As for Milwaukee, that city has long been liberal.
The reality is that technology will inevitably advance. I'll let lawyers debate the probable-cause issue, but concealed-carry holders need to remember that the "concealed" aspect is for avoiding detection by criminal elements and preventing a public panic, not concealing the weapon from the authorities.
The answer to preventing abuse by authorities in this regard lies in holding individual authority figures responsible for their actions. Sheriffs and police chiefs who issue illegal and unconstitutional anti-gun policies *cough MILWAUKEE cough* should be removed and penalized, and officers on the street applying them as if they were "the law" *cough CANTON, OHIO cough* need to be sharply disciplined.