CNET has up a blog post examining the question: does the Fourth Amendment apply to data stored in the Cloud? The US constitutional amendment forbidding unreasonable searches and seizures is well settled in regard to the physical world, but its application to electronic communications and computing lags behind. The post's argument outlines a law review article (PDF) from a University of Minnesota law student, David A. Couillard. "Hypothetically, if a briefcase is locked with a combination lock, the government could attempt to guess the combination until the briefcase unlocked; but because the briefcase is opaque, there is still a reasonable expectation of privacy in the unlocked container. In the context of virtual containers in the cloud...encryption is not simply a virtual lock and key; it is virtual opacity. ... [T]he service provider has a copy of the keys to a user's cloud 'storage unit,' much like a landlord or storage locker owner has keys to a tenant's space, a bank has the keys to a safe deposit box, and a postal carrier has the keys to a mailbox. Yet that does not give law enforcement the authority to use those third parties as a means to enter a private space. The same rationale should apply to the cloud." We might wish that the courts interpreted Fourth Amendment rights in this way, but so far they have not.