... before considering mandatory data retention. Absent compelling reasons justifying the indiscriminate collection of data that is inherent in any broad-based data retention scheme, its drawbacks and ... had a reasonable period of first-hand experience using the accumulated data in the investigation and prosecution of crimes against children. Only if data preservation has been shown to be ineffective ... appropriately.78, 79 These “call detail records” contain at least the following information: the calling number, called number, the date and time of the call, call duration, and other information...