The alleged scammers use the stolen Social Security numbers to file fake documents from companies purporting to withhold tax, then fake returns that are structured to ensure the filer is owed a refund.

WSJ: Billions Lost in Tax-Refund Scam

The moral of this story is that information hoarding in order to leverage Big Data tools may work in the structured data world, but will not work in the broader information world that includes unstructured content (the Word file, PowerPoint presentations, CAD files, audio files, and other large data types that dominate corporate information stores).

FORBES: Information Governance Even More Important In The Era Of Big Data