Sen. Dianne Feinstein, D-Calif., chair of the Senate Intelligence Committee, defended the credibility of the secret Foreign Intelligence Surveillance Court on Tuesday, citing a letter from the court’s presiding judge outlining the court’s review process.In a letter dated Oct. 11, 2013, Reggie Walton told Feinstein that nearly a quarter of government requests for surveillance made to the FISA court, which interprets the laws that govern the nation's intelligence practices, undergo “substantive” changes before being approved. “This statement from the presiding judge of the FISA Court makes it clear the court does not ‘rubber stamp’ requests for surveillance of terrorism suspects,” Feinstein said in an e-mail press release. “In fact, one in four applications undergo substantial revisions during the court’s review process and others are withdrawn entirely. The FISA Court is tasked with conducting careful legal analysis of all administration requests, and these data reinforce my belief that the FISA Court is taking that mandate seriously.” Walton said that between July 1, 2013, and Sept. 30, 2013, 24.4% of the government's requests were either substantially changed or withdrawn through the court’s review process. The numbers offer a different take on the tens of thousands of government requests made to the secret court, which according to annual reports to Congress, have totaled nearly 40,000 in the course of its 33-year existence. Only 9 of those applications were fully denied a number that intelligence officials have attributed to the court's review process.