As Congress considers legislation addressing when and how law enforcement can track cell phone data, lawmakers in Maine are taking steps at the state level towards tightening restrictions. Last night, the Maine Senate approved a bill that requires law enforcement to get a warrant before tracking cell phone data. But what's being hailed as a victory for civil rights is seen as a defeat for public safety by opponents of the bill. They said if the bill is enacted, police will lose access to a valuable crime-solving tool.