NY Times 
July 22, 2013
About 96 percent of all new vehicles sold in the United States have the boxes, and in September 2014, if the National Highway Traffic Safety Administration has its way, all will have them.
The boxes have long been used by car companies to assess the performance of their vehicles. But data stored in the devices is increasingly being used to identify safety problems in cars and as evidence in traffic accidents and criminal cases. And the trove of data inside the boxes has raised privacy concerns, including questions about who owns the information, and what it can be used for, even as critics have raised questions about its reliability.
To federal regulators, law enforcement authorities and insurance companies, the data is an indispensable tool to investigate crashes.