Mark Cuban, who has been sued by the SEC for insider trading, has filed a lawsuit over his FOIA requests for records pertaining to the SEC's investigations of him.
I haven't seen the lawsuit yet (his lawyers reportedly sent a copy to the AP but I couldn't find a link to it), but my take is that the SEC will argue these records are part of the ongoing investigation of Cuban and are protectible at this time pursuant to FOIA exemption 7(A). I'm also not sure why he isn't entitled to these records under criminal discovery under the case the SEC has against him.