Can information gathered under a FISA warrant be used to get another court to grant an Article III warrant, and can such information be critical to getting an Article III warrant? If a rubber stamp like FISC enables the government to get Article III warrants that it would not otherwise get, then FISC might as well just hand out Article III warrants.
It's not a rhetorical question, I don't know the answer to it one way or the other.
As to your second sentence, I think it's very reductionist. I see a FISC warrant as functioning like a subpoena. Say the SEC subpoena's your company's financial records from your accountant, and finds in there evidence that is sufficient to get a proper warrant to get documents from your company's premises. Does that mean there is no protection or purpose to the SEC not just being able to give itself Article III warrants?
