US v. Brown, No. 15-30148 (6-12-17)(Tigar w/Paz; Bybee dissenting). The ability to present a defense, to make an argument that the government has not proved the essential elements, is fundamental to the Sixth Amendment.  The 9th reverses a conviction, and remands, because the district court precluded the defendant from arguing that he had not posted a "notice" or an "advertisement" seeking or offering child porn on a "closed" restricted computer illegible board.

The government prosecuted the defendant under 18 U.S.C. § 2251(d)(1) for advertising child porn. The defense argument was that any notice on the computer bulletin board was not advertisement because of the closed restricted nature of the circle of users on Dark Moon. The court held that as a matter of law, posing on closed bulletin boards was advertisement.

On appeal, the 9th parsed the cases, especially US v Grovo, 826 F.3d 1207 (9h Cir. 2016), which held, on appeal, that posting on a closed bulletin board could be considered advertisement.  The 9th distinguished the case, finding that sufficient evidence to support a verdict, or to hold legally that posting on a closed bulletin board could be advertisement, is different from arguing to the jury that the government failed to prove that such posting was advertisement.  This is a jury question.  The preclusion prevented he defendant from presenting a case.

Dissenting, "vigorously ", Bybee argues that Grovo controls and that the majority invites a jury nullification argument.

The decision is here:

http://cdn.ca9.uscourts.gov/datastore/opinions/2017/06/12/15-30148.pdf