"In all, five justices said physically attaching the GPS device to the underside of a car amounted to a search requiring a warrant. Four justices, however, said the prolonged GPS surveillance in this case - a month - amounted to a search requiring a warrant, but was silent on whether GPS monitoring for shorter periods would require a warrant. All nine justices agreed to toss a District of Columbia drug dealer’s life sentence who was the subject of a warrantless, 28-day surveillance via GPS."
I'm curious if they threw out the drug dealer's case entirely or just the sentence, and whether or not it can be re-tried again without the GPS evidence.
Aside from the privacy implications, I think the thing that bothers me the most is technology replacing "good ol' fashioned police work." I was on the jury for one trial, and it was a drug bust. Guy was charged with three counts of selling marijuana to a minor, one count of selling. It was all to the same informant (whom the police had busted and turned to get at the defendant), but the informant turned 18 during the scope of the investigation. The prosecution had fingerprints, photographs, witness testimony, etc., and we convicted the defendant on three of the four counts. Of course, the whole case was screwy from the start: the lead detective's sister (caucasian) was dating the defendant (black) in Morman Mesa. We the jury wondered if the defendant would have been pursued quite so vigorously if he hadn't been involved with the detective's sister.
http://www.wired.com/threatlevel/2012/01/scotus-gps-ruling/