15. A computer program product in a non-transitory computer-readable storage medium in a data processing system, the computer program product holding computer program instructions which, when executed by the data processing system, perform a method of identifying potential confidential information in a data item, the data item associated with a source, the method comprising: obtaining, from each of a set of alternative sources, a data item of a same type and format as the data item; comparing the data item to the data item(s) obtained from the set of alternative sources to identify occurrences of particular pieces of information in the data item, wherein multiple occurrences of a particular piece of information within a data item from each alternative source are treated as a single occurrence; and based on the occurrences of particular pieces of information in the data item and a given sensitivity criteria, and without knowledge that the particular pieces of information are considered by the source to be confidential, segmenting one or more pieces of information in the data item as representing the potential confidential information.
16. The computer program product as described in claim 15 wherein the method further includes highlighting the one or more pieces of information.