1. A Privacy Preserving Data-Mining Protocol, operating between a secure “aggregator” data processor and at least one of “source-entity” data processor, wherein the “aggregator” and the “source-entity” processors are interconnected via an electronic data-communications topology, and the protocol includes the steps of: A) on the side of the “aggregator” processor: (i) from a user interface—accepting a query against a plurality of the predetermined attributes and therewith forming a parameter list, (ii) via the topology—transmitting the parameter list to each of the “source-entity” processors, (iii) via the topology—receiving a respective file from each of the “source-entity” processors, (iv) aggregating the plurality of files into a data-warehouse, (iv) using the parameter list, extracting query relevant data from the data-warehouse, (vi) agglomerating the extract, and (vii) to a user interface—reporting the agglomerated extract; and B) on the side of each processor of the at least one “source-entity” processors: (i) accumulating data-items wherein some of the data-items have privacy sensitive micro-data, (ii) organizing the data-items using the plurality of predetermined attributes, (iii) via the topology—receiving a parameter list from the “aggregator” processor, (iv) forming a file by “crunching together” the data-items according to the parameter list, (v) filtering out portions of the file which characterize details particular to less than a predetermined quantity of micro-data-specific data-items, and (vi) via the topology—transmitting the file to the “aggregator” processor.