The Cuyahoga County Court of Appeals just issued a new ruling addressing the ongoing development of law regarding police using GPS devices attached to cars (so they can track a suspect's movements). In 2012, the Supreme Court of the United States (in the case of United States v. Jones) held that you need to get a search warrant to do this. The police in this recent Ohio case claimed that since the Jones case was not the law at the time they placed their device, they had a "good faith" belief that what they were doing was legal at that time. The Cuyahoga County Court of Appeals disagreed with the police here. In short, if the police want to track a defendant's car with an attached GPS device, they gotta get a warrant - something that probably will not be too hard to do.