It's fascinating that the situation is such a mockery of the rule of law, yet it keeps on rolling. If the FISA decided that the NSA's activities were illegal, why would it keep rubber-stamping the warrants? It seems like at that point it should deny every single request going forward until the illegal activities have stopped. Is there a process for impeaching the FISA judges for malfeasance?
It's a matter of official policy to include legal loopholes that enable the Federal government to assert its power rather than comply with the law.
[1] Sir Humphrey Appleby, Jobs for the Boys (e/o "Yes Minister"), Jay A and Lynn J, BBC; first broadcast April 7, 1980.