The Obama administration will tell federal judges in New Orleans today that warrantless tracking of the location of Americans' mobile devices is perfectly legal.
Federal prosecutors are planning to argue that they should be able to obtain stored records revealing the minute-by-minute movements of mobile users over a 60-day period -- in this case, T-Mobile and MetroPCS customers -- without having to ask a judge to approve a warrant first.
Source: CNet. Read full article. (link)