In a 5-4 decision the Supreme Court has ruled that cops need a warrant to get a person's past location from wireless carriers. However, this ruling didn't touch on real-time location information to track suspects. Further, I haven't read the majority decision or the dissenting opinion, but I tend to lean towards anything that restricts the government from prying too deeply into my life so I have to say I agree with the ruling at first glance. The decision was issued during a time of rising concern over surveillance practices of law enforcement and intelligence agencies and whether companies like wireless carriers care about customer privacy rights. The big four wireless carriers—Verizon Communications, AT&T, T-Mobile US and Sprint—receive tens of thousands of these requests yearly from law enforcement.