IR sensors used on a home constituted a search so could not be used without a warrant. This would likely end up in a similar ruling, especially since it can provide more detail than that the walls and roof are hotter than they ought to be.
That's a very narrow victory though.
Yes, but at least three major parts of the dissenting opinion do not apply to backscatter machines.
First, Justice Stevens argued that heat emissions can easily be detected by the general public by a variety of means that do not involve special equipment.
Secondly, he argued that heat emissions are a part of the public domain once they leave the home, and are therefore fair game for inspection.
Finally, he argued that because the data provided by the sensors was incredibly crude, and gave no specific details about the home's contents, their use did not constitute a search.
And while I disagree on the whole, all of those are at least reasonable points that a sane person could make regarding IR sensors. But they utterly disintegrate if you switch to talking about firing x-rays into someone's home or car and generating a detailed image of its contents.
I can see an eager SWAT team ready to raid that family house on the corner because since they have those shields they must be terrorist, or at least doing something illegal!
In addition to privacy, I'm just as concerned about the potential danger of exposure to X-rays.
I wonder how long it'll be before things like this become "prohibited items" to regular citizens to own: http://www.cooking-hacks.com/index.php/documentation/tutoria...
A network of those with bluetooth or wifi connections, spread around critical intersections around the place where you're particularly concerned about your privacy could give you more than enough time to reconfigure things into something that'll look quite different on an x ray screen...
*Or the sort of people who construct IEDs?
But I understand the 4th Amendment to engender a freedom from scrutiny. If they don't have any reason to thing we're doing evil, they should mind their own business, regardless of the degree of physical intrusiveness involved.
Just having the government, or its computers, paying attention to us all the time violates this principle.
The intent of the BoR is just to keep the government from meddling, not to prevent the people, as those directly creating the culture and society, to react as they see fit. The government isn't permitted to stop us from saying bad things [2], but you're perfectly free to respond to the offensive comments of your neighbor. A court mind find someone innocent of a crime as a result of "technicalities" from the the 4th Amendment, but you're still free to shun a person that you believe to be evil.
[1] And, without explicit incorporation by the Court under the 14th Amendment, it applies only to the federal government and not the states. That seems pedantic, but it was only very recently that this was recognized for the 2nd Amendment, for example.
[2] Which doesn't stop them from doing so anyway; see recent legislation about cyber-bullying, for example.
Even though it's perfectly legal for a neighbor to notice something potentially suspicious about me (e.g. that I travel a lot or have a lot of guests), I don't think that taxpayer money should be used for concerted observational efforts without some form of court order.
so of course, disputes generally hinge on whether someone's subjective expectation of privacy is objectively reasonable or legitimate.
when i get a minute i'll edit this post with some examples!