1. A system, implemented on a computer comprising one or more processors, for providing transactional data privacy while maintaining data usability, comprising: a capture process, executing on the one or more processors, that monitors a first or source system, and captures a transaction containing one or more changes to data while the transaction is being received and committed at the first or source system; and an obfuscation process that receives a signal from the capture process when the capture process detects that the transaction is being committed, wherein meta-data associated with the data contained in the transaction includes a data structure describing a distribution of data values that is incrementally maintained, obfuscates the transaction using an obfuscation technique to create an obfuscated transaction, wherein the obfuscation technique includes a nearest neighbor data substitution process combined with anonymization whereby a distance between the data and an origin point is calculated, a nearest neighbor point in the data structure is determined, and a geometric transformation is applied to the nearest neighbor point, generating an obfuscated value, wherein at least some of the data contained in the transaction cannot be determined from the obfuscated transaction, and sends the obfuscated transaction back to the capture process for use in generating a trail file or other information to be sent to a target or second system, wherein the trail file or other information reflects the obfuscated transaction.