[tptacek]

It's not a lifetime position. Roberts position on the Supreme Court is a lifetime position. Absent a fundamental change to the US Constitution, Roberts is Chief Justice for life. But his position vis a vis the FISC is no more secure than that of the majority leader of the US Senate.

It's not exclusive. Exclusivity dictates that the power Roberts has is available only to him. But it's not; it's available to Congress as well. Not only that, but Congress' power over the FISC dwarfs that of Roberts. Congress could pass a law requiring FISC judges to decide while swinging upside down from a rope made of cheese curds. All Roberts can do is appoint FISC judges. Congress can un-appoint them.

It's not unaccountable. Unaccountable means that Roberts can exercise his power unchecked by any authority. Roberts power is checked the same way as the Secretary of Labor's power is: Congress can require him to testify before a committee and, if it wishes, strip him of his FISC power.