April 23, 2007
Open WAP and probable cause
The US 5th Circuit Court of Appeals has just handed down an opinion, U.S. v. Perez, --- F.3d ----, 2007 WL 1065784 (5th Cir. 2007), on a case where a man was convicted of possession of child pornography. Federal agents tracked him down through his IP address, which traced to his apartment. The defendant operated an unsecured wireless access point, and argued that this defeated probable cause, because anyone within a few hundred feet could have accessed the internet through that IP.
While not disagreeing with the technical facts, the court held that "though it was possible that the transmissions originated outside of the residence to which the IP address was assigned, it remained likely that the source of the transmissions was inside that residence." (Id. at 3).
It is worth noting that the court did not hold that the IP address proved that the defendant was guilty. No, it was the stacks and stacks of CD-Rs filled with porn that did that. Way to create a sympathetic public image for the judge, buddy.
All the IP address did was establish probable cause sufficient to swear out a warrant. This seems to make sense. Just because your IP address matches with undesirable activity doesn't prove anything, but it ought to be sufficient ground for interested parties to check you out.
The implications for file-sharing litigation are limited, as the vast majority of such cases are civil, not criminal (Justice has better things to do than prosecute college students). Probable cause doesn't really apply. Once the RIAA sues you, they can get your hard drive through the discovery process, no subpoena necessary. In both cases, what's on your hard drive is going to be a lot more important than your IP.
It's also worth pointing out that in civil litigation, the plaintiff need not prove his case beyond a reasonable doubt. If the RIAA has an alleged record of your IP downloading a file, and the file is on your hard drive... that looks bad. And looking bad is frequently enough to assign liability in civil cases. Saying "You can't prove it was me or that those files originated with your alleged download transaction" won't get you out of anything.
