The law enforcement agencies could track you throughout your situation, this would lead in more accurate calls, and a give the officers a better feel of what they are getting into before they even get there. It would also benefit in missing persons cases, where as the majority of the population has a cell phone this day if they have it on them at the time of the kidnapping then law enforcement could follow their location consistently. The only downside would be that not all phone companies would agree to share every customers location with law enforcement when needed.