Recently unsealed documents show that a federal judge has rejected an attempt by federal prosecutors to obtain the records of thousands of people who bought used books on Amazon. The records were sought as part of an investigation of a Robert B. D'Angelo, a Madison city employee who is accused of underreporting his income to tax authorities and operating a private business using city resources. The ruling was released after a federal grand jury handed down a 39-count indictment against D'Angelo.

The customers whose records the government was seeking were not suspected of any wrongdoing. D'Angelo is accused of selling used books and other merchandise via Amazon's website, using city time and resources to do it, and failing to report the income to the IRS. Prosecutors wanted to interview some of D'Angelo's customers to help build their case. They initially sought records from 24,000 customers, but after they encountered resistance from Amazon, they narrowed their request, seeking the records of 120 customers—30 from each of the four years D'Angelo is alleged to have operated his business.

In a June ruling, Judge Stephen Crocker rejected the government's demands for customers' private information, ruling that the First Amendment gives heightened protection to records concerning the sale of expressive works. However, he also acknowledged that the federal government had a legitimate need to contact some of D'Angelo's customers. He brokered a compromise in which Amazon agreed to contact a larger sample of customers asking for volunteers willing to talk to the feds. Those who declined to volunteer would have their privacy respected.

In a striking passage of his June decision, Judge Crocker acknowledges that the government's intentions were honorable, but nevertheless worries about the fallout that would result from a revelation that Amazon had turned over the purchasing records of thousands of book buyers. He predicted that news of the disclosure would "spread over the Net"—transmitted by sites like Ars, perhaps—and that "the chilling effect on e-commerce would frost keyboards across America."

In an interview published today with CNet's Declan McCullagh, Amazon VP for litigation David Zapolsky said that Amazon receives such subpoenas roughly once per quarter, and that the company will challenge any subpoenas that involve the "compelled disclosure of customer expressive choices." In most cases, he said, the government will modify or withdraw their request in response to Amazon's concerns. More rarely, Amazon will take the case to court and let the judge decide if the order is appropriate.

Zapolsky cites two cases that have bolstered Amazon's ability to mount First Amendment challenges to grand jury subpoenas of book-purchasing records. In one case, the Colorado Supreme Court sided with a Denver bookstore that was fighting the compelled disclosure of one of its customers' records. In the other case, special prosecutor Kenneth Star unsuccessfully sought records regarding Monica Lewinsky from Kramerbooks, a popular book store and restaurant in Washington, DC.