from the access device 132 if the access device is unable to provide the requested portion of a different song the verifier 126 can conclude that the media 130 is not actually present for rendering and will terminate subsequent rendering of the material that the user intended to render via the gate 124 for example a user may illicitly download a selection of different copy protected songs from a remote site 140 on the internet 144 and then attempt to create a compilation cd containing these user selected songs typically the size of an entire album of material discourages the downloading of each album that contains the user selected songs when the verifier 126 requests a portion of a different song from the album corresponding to an actual cd 130 the user who downloaded only the user selected song from the album will be prevented from further rendering of the downloaded material a variety of techniques may be employed to assure that the material provided in response to the request corresponds to the material that is contained on the actual cd 130 for example copending u s patent application u201c protecting content from illicit reproduction by proof of existence of a complete data set via self referencing sections u201d u s ser no 09 536 944 filed 28.