There is a really interesting case in Wisconsin that got a write-up in the Chicago Tribune. In the case, the judge ruled that the police did not violate the suspect's 4th amendment privacy rights when they acquired a warrant for and placed a GPS tracking device on his vehicle. The defendent in this case was suspected of stalking a woman. The police received a warrant, although there is no law that requires that they do so, in order to place the tracker on the defendent's vehicle. It was retrieved a few weeks later and the data on the tracker used to get a warrant to search his home and vehicle for further evidence of stalking. He was later found guilty.
It's a sticky legal situation. In my opinion, the judge made the right decision in upholding that the use of the GPS device was legal and did not violate the defendent's rights in any way. The judge expanded on the decision to make it clear that, although the police did get a warrant in this situation, there was no law that made that effort necessary. The judge clearly called this out to get attention for the issue (congratulations, it was a resounding success) and for legistlators to consider a law that would require a warrant for such use of GPS. So what do you think? Do you agree with the ACLU that the police must receive a warrant in order to place a GPS tracking device on your vehicle?
The 4th amendment is a slippery devil. It is the amendment that guards against unreasonable search and seizure. The definition of what is unreasonable is pretty subjective though. It is currently codified for telephone tapping as, (paraphrasing) "If you have a reasonable expectation of privacy, the government must seek a warrant". This means that when you use your home phone from your home, you have a reasonable expectation that your conversation is private. As such, the police need a warrant to listen in on that conversation. However, if you are at the mall chatting with your friend, you have no reason to expect that conversation to be private. Anyone present could easily eavesdrop, and so the police are also permitted to eavesdrop in that situation. Applying the same idea to your vehicle, anytime you travel on a public roadway you have no reasonable expectation that the information about your position is private. Police have and exercise the ability to track you, and this is how people get speeding tickets, traffic violations, citations, or pulled over for an outstanding warrant for their arrest. What's more, anything observable from public grounds is also considered to have no expectation of privacy. So if the police stand in the middle of the road and watch you park your car in the garage, the location of your car is public knowledge (until we catch up to Star Trek with transporter tech anyway). The judge applied this reasoning to say that the information on the position of the defendent's vehicle never had a reasonable expectation to privacy. Given this, the judge ruled that placing a GPS tracker on the vehicle was no different than having an officer tail the vehicle at all times, as the position of the vehicle would always be publicly knowable anyway.
The judge was hoping to get a reaction with the inclusion of the note that the warrant the police received in this situation was not required, and boy did he. The ACLU is sounding the alarm that this is a "gateway drug" of sorts for the government which will inevitably lead to every man woman and child wearing a tracking chip from birth to death. I don't believe that, but I do think it is an interesting question as to whether a warrant should be required for all GPS tracking of vehicles. On the one hand, I don't relish the idea of my location (which is tightly coupled to the location of my vehicle) being public knowledge. Even though it would be possible for any interested party to track me day and night, they don't. As such, I have a relative expectation that my whereabouts are unknown to all except for those I give that information to. In fact, it would be a bit of a danger if my location was always public. If you could easily determine that I was, say, out of state, it might present an enticing opportunity for a burglar to break into my home. Worse yes, someone with violence in mind would know when I at home or at work.
On the other hand, I believe that the scenario cited in the case was a just use of surveilance. It was carefully applied (only the suspect was tracked) and it resulted in someone who really was dangerous being apprehended. I also think to another use of GPS that is used in high speed chases. The police fire a "GPS canon" at a vehicle in a high speed chase. The GPS unit sticks to the vehicle, and the police can then drop off the chase and monitor the vehicle remotely, and thus greatly lessen the danger to the general public. High speed chases are very dangerous, and when a criminal is running he is much more likely to drive dangerously when he feels he is being pursued rather than when not. If warrants were required, either the criminal would require pursuing, thus increasing the danger to the public, or he could contend that the use of the GPS tracker was illegal and thus he must be let free. Either scenario is unsavory.
So is a law necessary to govern the use of GPS tracking units by the police? If so, how should the law be framed? No matter which way you think, the fact that our legislators will be debating it means that it is going to cost you some of your taxes, so it is worth being interested in the answer. If no warrant is required, it might lead to greater use of this technology without the careful application shown by the Wisconsin police. If warrants are required it may create an environment more permissive for those with ill intentions for doing harm to others. Personally, I think that in most cases a warrant is probably in order, although special exceptions should be made to permit applying a tracker in chase situations or other intense situations where the use of the device could alleviate an immediate danger to the public. What about you?