Many other outlets in the MSM (350 so far, according to a GOOGLE NEWS search I just ran) have portrayed this monitoring by the FBI as illegal and unconstitutional because these efforts at radiation detection were done without a court-order, and just based on intelligence. THIS IS WRONG. Here are two great analyses of the issues involved:
(1) From a commenter ("The Original TS") at VOLOKH who asked if measuring ambient gamma rays different from measuring infrared radiation emanating from a specific surface (which the SCOTUS has previously held does require a court order? [SEE: Kyllo v. United States.]
Yes, extremely different. First, gamma ray radiation can't be used for imaging. Infrared radiation can. One of the big Constitutional problems in Kyllo was that allowing the police to do infrared imaging would effectively mean that everyone was living in glass houses without curtains.
Measuring radioactivity does not present the same issues. It's more aking to "smell" than it is to "sight." While it is improper for the police to use infrared detectors to "see" a drug lab from the street, there is no problem with "smelling" a drug lab from the street.
Another point is that, unlike infrared imaging, measuring radiation is extremely unlikely to reveal legal activity. Everything emits infrared radiation, especially, people. Hardly anything emits high levels of radiation, especially people. In fact, I'd be willing to bet (though I don't actually know for sure) that possessing something that is highly radioactive is a per se violation of some federal statute. In other words, at some level, radiating your neighborhood is a crime in and of itself.
The point here is that measuring radiation levels is not violating anyone's privacy since it won't provide information regarding legal activities.
Generally speaking, can law enforcement authorities use nuclear detection devices against someone's house without a warrant? This question is at root of the latest "no warrant" controversy.
Readers would do well to examine the Supreme Court case Illinois v. Caballes, decided earlier this year. The Court ruled that when a dog sniffed out drugs during a routine traffic stop, without a warrant, it did not constitute an illegal search because, in the words of Justice Stevens,
"Official conduct that does not 'compromise any legitimate interest in privacy' is not a search subject to the Fourth Amendment. Jacobsen, 466 U.S., at 123." The Court noted that "any interest in possessing contraband cannot be deemed 'legitimate,' and thus, governmental conduct that only reveals the possession of contraband 'compromises no legitimate privacy interest.' Ibid."
Note that in an earlier case, Kyllo v. US, the Court ruled that thermal detection devices could not be used to surveil houses without a warrant because this would compromise privacy -- the difference being that such devices pick up licit as well as illicit activity. In his dissent in that case, Justice Stevens pondered whether "public officials should not have to avert their senses or their equipment from detecting emissions in the public domain such as ...radioactive emissions .. which could identify hazards to the community.
In my judgment, monitoring such emissions with 'sense-enhancing technology,' ... and drawing useful conclusions from such monitoring, is an entirely reasonable public service."
Clearly Caballes rather than Kyllo controls in the case of using detection equipment to pick up emissions from nuclear materials banned under 18 USC 831 since, to quote Stevens' majority opinion, such activity "reveals no information other than the location of a substance that no individual has any right to possess." And even if you want to subject this to a balancing test, I think the government would not have to argue very strongly that there is a compelling state interest in keeping nuclear weapons out of the hands of private citizens.
There's only one thing that will stop this spate of traitorous leaks: throw the leakers and those that published the leaks in jail - or execute them for treason. YEAH: I AM SERIOUS! These leakers are endangering millions of lives and trillions of dollars and our economy and our effort in the GWOT. They are traitors and should be tried and executed.