This Daily Kos Diary explains what happened in detail. A source inside the Utah government reports that this action was undertaken out of fear that the Rave would be used to rally support for the protest against Bush's Utah visit.
Download QT Thanks to One Good Move for the video.
Greatscat has this post about Utah refusing to air Cindy Sheehan's commercial stating: "inappropriate commercial advertisement for Salt Lake City." I guess this type of action is appropriate for Utah.