For instance....

snip:

Criticism

There has been growing criticism of the court since the September 11, 2001 attacks. This is partly because the court sits ex parte – in other words, in the absence of anyone but the judge and the government present at the hearings.[3] This, combined with the minimal number of requests that are rejected by the court has led experts to characterize it as a rubber stamp (former National Security Agency analyst Russ Tice called it a "kangaroo court with a rubber stamp").[15] The accusation of being a "rubber stamp" was rejected by FISA Court president Reggie B. Walton who wrote in a letter to Senator Patrick J. Leahy: "The annual statistics provided to Congress by the Attorney General ... – frequently cited to in press reports as a suggestion that the Court's approval rate of application is over 99% – reflect only the number of final applications submitted to and acted on by the Court. These statistics do not reflect the fact that many applications are altered to prior or final submission or even withheld from final submission entirely, often after an indication that a judge would not approve them."[16] He added: "There is a rigorous review process of applications submitted by the executive branch, spearheaded initially by five judicial branch lawyers who are national security experts and then by the judges, to ensure that the court's authorizations comport with what the applicable statutes authorize."[17] In a following letter Walton stated that the government had revamped 24.4% of its requests in the face of court questions and demands in time from July 1, 2013 to September 30, 2013.[18][19][20] This figure became available after Walton decided in the summer of 2013 that the FISC would begin keeping its own tally of how Justice Department warrant applications for electronic surveillance fared – and would track for the first time when the government withdrew or resubmitted those applications with changes.[20] Some requests are modified by the court but ultimately granted, while the percentage of denied requests is statistically negligible (11 denied requests out of around 34,000 granted in 35 years – equivalent to 0.03%).[6][15][21][22] The accusation that the FISC is a "rubber stamp" court was also rejected by Robert S. Litt (General Counsel of Office of the Director of National Intelligence): "When [the Government] prepares an application for [a section 215 order, it] first submit[s] to the [FISC] what's called a "read copy", which the court staff will review and comment on. [A]nd they will almost invariably come back with questions, concerns, problems that they see. And there is an iterative process back and forth between the Government and the [FISC] to take care of those concerns so that at the end of the day, we're confident that we're presenting something that the [FISC] will approve. That is hardly a rubber stamp. It's rather extensive and serious judicial oversight of this process."[23]

A 2003 Senate Judiciary Committee Interim Report on FBI Oversight in the 107th Congress by the Senate Judiciary Committee: FISA Implementation Failures cited the "unnecessary secrecy" of the court among its "most important conclusions":

The secrecy of individual FISA cases is certainly necessary, but this secrecy has been extended to the most basic legal and procedural aspects of the FISA, which should not be secret. This unnecessary secrecy contributed to the deficiencies that have hamstrung the implementation of the FISA. Much more information, including all unclassified opinions and operating rules of the FISA Court and Court of Review, should be made public and/or provided to the Congress.[24]

Allegations of bias

and much more

https://en.wikipedia.org/wiki/United_States_Foreign_Intelligence_Surveillance_Court#Secrecy