Data mining, when done correctly, can improve understanding and provide insight, but data mining just doesn’t work under stupid assumptions. Check out the following paragraph in a Wall Street Journal blog. Apparently some FBI agents assume hummus sales to be predictive of terrorist activity.
The FBI obtained and mined sales data that San Francisco-area grocery stores collected in 2005 and 2006, according to CQ Politics. The agents were looking for a sudden spike in hummus sales that might indicate an Iranian sleeper cell in the Bay Area. An FBI higher-up killed the program, CQ Politics reports, on the grounds that it might be illegal and that it was, well, just ridiculous.