Major labels have been hit with a setback in Arizona today, where a federal District Court judge denied their motion for a summary judgment filed against alleged Kazaa file sharers Pamela and Jeffrey Howell.

Contrary to some other court decisions, this court held that making a music file available in a Kazaa shared folder is not an unlawful distribution of a copyrighted work. To infringe the right of distribution under copyright law, the owner must prove the "actual dissemination of copies or phonorecords," the court held.

In other words, copyright owners must prove that the file was actually downloaded by someone.

In this case, while the labels' investigator downloaded 12 files, there is no evidence that either the investigator or any Kazaa user downloaded the remaining 42 recording listed as being infringed in the suit, the court wrote. As a result, only the 12 recordings will be considered as works allegedly infringed.

The court also held that the labels must prove at trial that Howell was responsible for sharing the files.

"This is a strange decision that is outside of the mainstream and inconsistent with countless court rulings on these issues," the RIAA said in a statement. "We are currently considering all options going forward."

Since this is a District Court decision rather than a federal appellate decision, it only affects cases in that federal district in Arizona.