For weeks, we've all been trying to determine whether the Foreign Intelligence Surveillance Court is a rubber stamp or an effective check on the NSA's broad surveillance powers. The Obama administration insists that FISC's existence is evidence that the system works. Critics of the court say it is either complicit with the NSA or powerless to resist it.

New documents released by Obama's top spy today offer ammunition to the critics.

In a 2011 court opinion, the FISA court repeatedly accuses the NSA not only of failing to comply with the rules, but of misleading it outright.

Here's a footnote in the same document saying much the same thing:

The footnote amounts to a court admission that it had been allowing the NSA to proceed for years without a full understanding of the surveillance program. On the next page, the court suggested that the NSA breached criminal law and threatened to follow up with a separate court order:

These passages underscore previous statements by the FISA court's presiding judge, Reggie Walton, arguing that FISC only has a limited ability to investigate abuse and can only make decisions based on information the NSA provides.

This document suggests that the FISA court is not the rigorous check on NSA abuses that the Obama administration has claimed it is.