A data privacy management system includes a data repository, a private data mediating system and a privacy manager. The data repository stores private data items in an obfuscated form. Each private data item has associated privacy policy data a defining conditions to be met to ensure the privacy of the data item. A private data mediating system communicates with the privacy manager to obtain de-obfuscated private data items that are extracted from the data repository 10. De-obfuscation of the data 51, 53 is subject to satisfaction of the privacy manager that the respective conditions ensuring privacy of the data item are met.