'The Surprisingly Weak Reasoning of Mohamud'

Over at Lawfare, I have a long post criticizing the reasoning of the Ninth Circuit's decision in United States v. Mohamud, on the Fourth Amendment implications of monitoring under Section 702 of the Foreign Intelligence Surveillance Act. The post builds on some criticisms I flagged here on the day the case was decided.

From the introduction:

In a recent post here at Lawfare, April Doss argues that the Ninth Circuit's decision in United States v. Mohamud "got it right." In her view, the critics of the decision—myself included—are just wrong. I disagree. Here's why I think the reasoning of the decision is hard to defend.

First, an important caveat: My argument is about reasoning and not result. A lot of discussion on Mohamud focuses on the bottom line of which side won. That's understandable, but it's not my concern. My concern is whether the reasoning of the case makes sense as a matter of Fourth Amendment law.

When viewed from that perspective, Mohamud strikes me as awkward and unconvincing. Its core holding is weak and hard to square with Supreme Court doctrine. Other parts of it border on the incoherent. And it could have reached its result much more easily without the conceptual wrong turns.

I have a lot of respect for the judges on the panel, and normally I wouldn't go back to the issues I flagged in my first post to add on more. But the Ninth Circuit panel is the first appellate court to get into these issues, and the issues are really important to the future of the Fourth Amendment. Given that, I thought it was worth going into more detail about why I think the decision is problematic.