All shops have to do is log deliveries and pick-ups through a website that automatically sends e-mail and text-message alerts to addressees.

ECONOMIST: Package pick-up services are set to prosper

All that remains is finding a name or two for the addressees.

FORBES: There's A Man Going Around Faking Names: The Al Qaeda Shipping Dept.

The refund checks are mailed to the addresses on the forged documents even though the addressees don't live at those locations, which is why some postal workers have been recruited, according to people briefed on the investigations.

WSJ: Billions Lost in Tax-Refund Scam