viodentia (sometimes written with an uppercase v) is a pseudonym used by the creator of FairUse4WM, a program that removes Microsoft's copy protection technology from Windows Media Video (".WMV") files. These files are used by popular music download sites such as Rhapsody, Yahoo! Music, and Napster. A number of prominent websites use digital rights management ("DRM", a form of copy protection) to ensure that media and other downloads are unable to be copied for software piracy or other improper purposes.