They already have Brennan through whistleblower Dennis Montgomery. Judge Snow as well took all of the recordings/documents.
Recordings background info at this link.
http://themillenniumreport.com/2017/03/the-hammer-ultra-secret-supercomputer-system-used-by-ciansa-to-wiretap-trump/
Audio at the link. "The Hammer" being the Supercomputer name. Montgomery went to Comey ages ago with 47 HD's over 600 million pages of documents. Sara Carter reported on this yikes back in early spring? of 2017.
>themillenniumreport.com/2017/03/the-hammer-ultra-secret-supercomputer-system-used-by-ciansa-to-wiretap-trump/
Montgomery property receipts from FBI.