the courts have usually interpreted the fourth amendment based on the effects of technology, not the mechanisms of technology. they don't have to understand how stingrays work, they only have to understand what impact stingrays have on your freedom from search.
that's why the court ruled that thermal imaging (in kyllo v us) is a search. sure, the mechanism of the technology is that you're carelessly broadcasting your heat signature through the airwaves, but the effect is the same as if the police had entered the home - they can see inside it.
that's why the court ruled that thermal imaging (in kyllo v us) is a search. sure, the mechanism of the technology is that you're carelessly broadcasting your heat signature through the airwaves, but the effect is the same as if the police had entered the home - they can see inside it.