There are three varieties of "Kelsey's Law" in the world -- or at least the U.S. right now.
The first type is named in memory of Kelsey Smith, a 16-year old teenager abducted, raped, and murdered in Kansas back in 2007, and seeks, on the state level, to mandate cellphone carriers provide law enforcement tracking & location data in emergencies. Federal law allows wireless companies divulge information to law enforcement agencies, but these would make it mandatory for the state in which enacted.
USAToday reported last Monday that this Kelsey Law variety "has steadily been gaining ground since Kansas' was passed in 2009; Nebraska, Minnesota, and New Hampshire enacted their versions in 2010, followed by North Dakota in 2011 and Hawaii & Tennessee earlier this year." Illinois, Massachusetts, the U.S. House of Representatives and the Canadian province of Albany are also reported to be considering similar legislation.
Missouri became the 8th. state in the nation, Tuesday, to enact a this version of Kelsey's Law ( Here ) , but already has it being challenged in Western Missouri District Court with claims that "Missouri's mandate for phone companies to supply information to police clashes with a federal law, giving cellphone providers discretion in determining whether a police request truly constitutes an emergency that would justify sharing information without a court order or subpoena." It seeks a restraining order or injunction prohibiting enforcement of Missouri's law, and class action status to represent all cellphone subscribers in the state. (News articles here & here; Complaint here )
Six years ago in May 2006, Oklahoma passed a bill that came to be known as the "Kelsey Smith-Briggs Child Protection Reform Act," bearing the name of a slain 2-year old girl that improved training of court-appointed child care advocates and made judges more accountable for their rulings in child-placement cases. ( Bill and Article… now part of Title 10 Chapter 70)
The last variety of "Kelsey Laws" is represented by a bill currently in the Michigan Senate which was elected to named it "Kelsey's Law" in honor and memory of Sault Ste. Marie teenager Kelsey Raffaele, who was killed when she crashed her car while talking on her cellphone. Her mother has lobbied lawmakers to pass such a ban and encouraged teenagers to not use their cellphones while driving. ( Bill and Article )
Coincidentally, Ohio's new driving & texting law also goes into effect tomorrow ( Bill analysis and Article )