Two weeks ago, in United States v. Rosenow, the Ninth Circuit handed down a decision that has a brief but truly stunning passage with major implications for the future of Fourth Amendment law. If the passage stays in the opinion, it's going to have a quite dramatic effect, perhaps inadvertently, on how the Fourth Amendment applies to computers and the Internet. And in my view, those effects are bad. Really, really bad. In this post, I want to say why the passage in Rosenow is so important, and why it's so disturbing. And I'll suggest a possible path forward to deal with it.
I. An Overview of the Rosenow Case
Rosenow arose out of an investigation into child exploitation in the Philippines. Two large Internet providers, Yahoo and Facebook, ended up being involved. That led eventually to Rosenow's arrest on his return from the Philippines to the United States and a search through his computers pursuant to a warrant. The search revealed child sexual abuse material (CSAM), also known as child pornography, including some involving sexual acts between Rosenow and prepubescent Filipina girls. On the basis of the images found on his computer, Rosenow was convicted of sexual exploitation and CSAM possession.
