[Ernest_at_the_Beach]

They have to reside within a number of miles of DC.

Very interesting and would explain why they were chosen...

[mware]

Here is the rule regarding living in DC.

The Foreign Intelligence Surveillance Court was created by section 103(a) of the Foreign Intelligence Surveillance Act of 1978 (50 U.S.C. 1803(a)). It was originally comprised of seven district judges from seven circuits named by the Chief Justice of the United States to serve a maximum of 7 years.

In 2001, the U.S.A. Patriot Act (section 208) amended the Foreign Intelligence Surveillance Act to increase the number of FIS Court judges from seven to eleven, "of whom no fewer than 3 shall reside within 20 miles of the District of Columbia."

[AmishDude]

At least 3 have to reside in or near DC. As many as 8 do not have to. I'm sure this is so that a 3-judge panel can be convened in an emergency.