I have just posted a draft of a forthcoming essay, Fourth Amendment Seizures of Computer Data, forthcoming in the Yale Law Journal.

  Here's the abstract:

What does it mean to "seize" computer data for Fourth Amendment purposes? Does copying data amount to a seizure, and if so, when? This essay argues that copying data "seizes" it under the Fourth Amendment when copying occurs without human observation and interrupts the course of its possession or transmission. It offers this position by reaching back to the general purposes of regulating seizures in Fourth Amendment law and then applying that function to the new environment of computers. The test prevents the government from copying data without regulation and yet also meets and answers the objections that have puzzled scholars and made it difficult to apply the old definition of seizures in the new computer environment.

  Also, here's the end of the introduction:

Finally, this essay offers a correction of some of my prior work. In a 2005 article published in the Harvard Law Review, I concluded somewhat uncomfortably that copying should never be considered a Fourth Amendment seizure. At the time, I was influenced by the cases holding that photographing and writing down numbers were not a seizure, as well as by what seemed to be considerable practical problems with calling all copying a seizure. I now see I was wrong. A middle ground is not only possible but also most consistent with both the cases and common sense. This essay identifies the new middle ground and explains why I now disavow my earlier approach.

As always, comments welcome.