Microsoft last week killed the Office Genuine Advantage anti-piracy service that first checked — and later nagged — whether customers were running legal copies of Office. ZDNet blogger Ed Bott first reported on Microsoft's move after a tipster pointed him toward a support document on the company's site. That Dec. 17 document simply noted that Office Genuine Advantage 'has been retired,' but offered no explanation. A Microsoft spokeswoman told Computerworld on Monday, 'The program has served its purpose and thus we have decided to retire the program.