The memo drafted by Rep. Devin Nunes of the House Intelligence Committee alleged abuses of the Foreign Intelligence Surveillance Act (FISA) by the FBI and the Department of Justice.

Why it matters: There are a lot of myths about FISA, its associated courts, and the approval process the DOJ must go through to get a warrant to conduct surveillance. And questions remain about the application regarding the FBI's decision to surveil Carter Page following the memo's release.

Here's what you need to know about what FISA is and how the application process works.

What is FISA?

Signed into law in 1978, FISA requires the government to obtain permission from a judge on the Foreign Intelligence Surveillance Court (FISC) in order to surveil communications on domestic soil for national security reasons.

requires the government to obtain permission from a judge on the Foreign Intelligence Surveillance Court (FISC) in order to surveil communications on domestic soil for national security reasons. The FISC, also established in 1978, along with judges appointed by the Chief Justice of the Supreme Court, makes decisions as to whether to approve wiretaps, data collection, and government requests regarding monitoring suspected terrorists and spies. Eleven federal district judges sit on the court on a rotating basis.

How does the FISA application work?

In criminal investigations, the FBI can seek a warrant under Title III of the U.S. criminal code by showing a federal court that there is probable cause to believe the target has engaged, or is engaging in, criminal activity.

For electronic surveillance, the government has to show that the target might be spying for a foreign government or organization.

How do FISA applications get approved?

FISA warrant investigations can’t be opened “solely on the basis of First Amendment activities." In other words, affiliation with questionable parties isn't enough to warrant a FISA case.

Evidence the FBI can use to support the claim that the U.S. target is knowingly working on behalf of a foreign entity can include information gathered from human sources, physical surveillance, bank transactions, or even documents found in the target’s trash.

information gathered from human sources, physical surveillance, bank transactions, or even documents found in the target’s trash. Once evidence has been accumulated, the information must be outlined in an affidavit and application stating the grounds for the FISA warrant.

The completed FISA application goes through the FBI chain of command, before making its way to FBI Headquarters to receive approval and sign off by the Special Agent in charge of the field office before making it to the Justice Department where attorneys from the National Security Division vet the application to verify all the assertions made in it.

The FISC then reviews the application in secret, and decides whether to approve the warrant.

Myths

It’s easy to get a FISA warrant. Although it’s true that statistics show judges rarely deny applications for FISA warrants or criminal wiretaps, the government rarely submits applications that aren’t approved because there are are several rounds of conversations the Department of Justice must go through in order to obtain warrants, per the NYT.

The FISC received 1,752 applications in 2016, granted 1,378 orders, modified 339, denied in part 26 orders, and denied in full 9 applications, according to FISC disclosures.

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