Is anyone aware that Universal Music Group, whose labels include Decca, Deutsche Grammophon and many others, is digitally watermarking their audio files in a way that produces very audible distortion of music? It adds a warbling or fluttering quality, most noticeable on sustained tones, and especially on piano music. It apparently is also being used on lossless tracks which are being sold as perfect copies of CDs. For the technical details see Matt Montag's blog here:
What do we do about this? Complaining to UMG isn't likely to help; their contempt for their customers is obvious.