Microsoft is suing the hacker who released software to remove DRM code from Windows Media Player. According to ZDNet, Vole claims that somehow the unknown developer had gained access to its copyrighted source code to carry out his hack so effectively.

The copyright lawsuit was filed in Seattle federal court last Friday, without a name attached. Just as in the recording industry's many lawsuits against accused file swappers, it targets an unknown individual or individuals, whose true identity will be sought in the course of the case. For now, that means going to the Internet service providers for Web sites where the original FairUse4WM tool was released, in hopes of tracking down an IP address or other digital traces that might lead to the developer, MacNaughton said.

Microsoft is also contacting other Web sites that have posted the FairUse4WM tool, asking them to remove the software, on the grounds that it contains copyrighted company code. Company representatives declined to speculate on exactly how "Viodentia" gained access to copyrighted source code. The code in question is part of a Windows Media software development kit, but is not easily accessible to anyone with a copy of that toolkit, Microsoft said.  So far, little is known about the developer, who has used the pseudonym "Viodentia" in several online postings at a site called Doom9.org. "Viodentia" could not immediately be reached for comment.

Update: Viodentia today releases FairUse4WM 1.3