Turns out last week's explosive packages from Yemen weren't the first intercepted—packages shipped from Yemen in September were also searched by U.S. counter-terrorism officials. When they were found to hold household items like books and CDs, they were forwarded to their destination. Now officials are speculating that these packages were a practice run for a terrorist attack.

Via the NYTimes:

In September, after American counterterrorism agencies received information linking the packages to Al Qaeda in the Arabian Peninsula, the terror network’s branch in Yemen, intelligence officers stopped the shipments in transit and searched them, said the officials, who would discuss the operation only on the condition of anonymity. They found no explosives, and the packages were permitted to continue to what appeared to be “random addresses” with no connection to the terrorist group in Chicago.

...The apparent test run might have permitted the plotters to estimate when cargo planes carrying the doctored toner cartridges would be over Chicago or another city. That would conceivably enable them to set timers on the two devices to set off explosions where they would cause the greatest damage.