DarkNoise's Q-Spoiler technology inserts data into digital audio files that has a combination of interesting properties.  The data is inaudible as long as the file is played as is.  But the nature of the inserted data is such that analog conversion or lossy compression treats it badly and produces very audible distortion in the resulting output.  It's analogous to certain ink techniques for printed documents that are nearly invisible but become highly visible on photocopies of the document, thereby making it clear that the document is not an original.  The data that Q-Spoiler inserts also acts as a watermark that stores a unique content ID and is very difficult to remove from the file.

This is a smart business move for QuietTiger and SunnComm -- provided, of course, that this untested and virtually unheard-of technology actually works in production -- because unlike its arch-rival Macrovision, SunnComm had been betting the company on a copy-protected CD technology that is looking worse and worse every day.  SunnComm needs a way of diversifying its business, and DarkNoise's technology is complementary to SunnComm's (despite the dichotomy between "Sunn" and "Dark").

However, DarkNoise has potentially disturbing ramifications for fair use and the balance of rights inherent in copyright law.  The DarkNoise technology is meant to address what media industry people call the "analog hole," i.e., the idea that there is no way to prevent copying of content when it's in analog form, such as recording a CD onto an audio tape, scanning and OCR-ing a publication, or camcording a movie in a theater.  Yet as much as the media industry bemoans the analog hole, media company copyright lawyers always offer it up as a sort of "workaround" to rigid DRM schemes for digital content as a way to exercise private copying or other so-called fair use rights. 

If technology such as DarkNoise can really close the analog hole, then there is opportunity for the media industry at large to abuse the technology and truly upset the balance of rights inherent in copyright law.  Consumer advocates should see big red flags in the Dark.