This seems to relate to using devices to detect things inside your car (dogs) or devices to detect growing lamps in your house (unconstitutional search).
It looks like they are working to erode searches again, using dogs to detect drugs inside a home. http://www.scotusblog.com/2012/10/argument-preview-drug-snif...
Everything I learned in high school civics class seems to be obsolete when it comes to our Constitutional rights: "bong hits for jesus", "administrative" searches (body scanners), and now street searches.
Why is it the argument from ignorance/lack of imagination via fear is so compelling? "We need to do X to stop Y." Where Y is something very remote but really scary.