clipped from blog.wired.com

Bay Area FBI agents wanting to find Iranian secret agents data-mined grocery store records in 2005 and 2006, hoping that tahini purchases would lead them to domestic terrorists, according to Congressional Quarterly's Jeff Stein. The head of the FBI's criminal investigations unit - Michael Mason - shut down the Total Falafel Awareness program, arguing it would be illegal to put someone on a terrorist watch list for simply sticking skewers into lamb, Stein reports.

The idea was that a spike in, say, falafel sales, combined with other data, would lead to Iranian secret agents in the south San Francisco-San Jose area.

The brainchild of top FBI counterterrorism officials Phil Mudd and Willie T. Hulon, according to well-informed sources, the project didn’t last long. It was torpedoed by the head of the FBI's criminal investigations division, Michael A. Mason, who argued that putting somebody on a terrorist list for what they ate was ridiculous — and possibly illegal.