Civil liberties advocates have long suspected that the Justice Department is underreporting Section 702 cases in order to limit court challenges to the controversial law. Some theorize that the government conceals Section 702 use through a process known as “parallel construction,” in which evidence obtained from the warrantless surveillance authority is reobtained through traditional FISA authorization, and the government only discloses the latter authority in U.S. District Court. One defense lawyer referred to this practice in a court filing as “laundering” Section 702 evidence. Beyond the Kurbanov case, circumstantial evidence in other  prosecutions suggests that this type of parallel construction could be widespread.

“The government intercepts Americans’ emails and phone calls in vast quantities. … Yet only a handful of individuals have ever received notice.”

“The government intercepts Americans’ emails and phone calls in vast quantities using this spying law and stores them in databases for years,” said Patrick Toomey, staff attorney for the American Civil Liberties Union’s National Security Project. “FBI agents around the country then go searching through that trove of data as a matter of course, including in domestic criminal investigations. Yet, over almost a decade, only a handful of individuals have ever received notice.”

The Justice Department, FBI, and NSA declined to comment for this article. The New York Times in 2013 reported that lawyers in the Justice Department’s National Security Division had believed they did not need to disclose in court whether evidence obtained through FISA specifically originated with Section 702 unless they were presenting material received directly from a Section 702 sweep. The U.S. solicitor general then successfully pushed for a change in policy, bolstered by fallout from the Snowden disclosures; this was followed by a review of past cases by the National Security Division, after which prosecutors filed supplemental Section 702 notices in a handful of cases around the country. In four such cases, the defendants had already been convicted by the time of the disclosure. And whatever changes occurred in 2013 were clearly limited, given that fewer than a dozen such notices have ever been given in court cases, and none at all has been filed in the last year and a half. Kurbanov, meanwhile, was convicted in 2015, well after the purported change in policy.