Shacknews has a story up speculating about the possibility that art assets from id Software's DOOM 3 and Valve's Half-Life 2 may be present in S.T.A.L.K.E.R.: Shadow of Chernobyl, GSC Game World's just-released shooter. They offer comparative screenshots to illustrate the theory, which is apparently bolstered by the fact that the suspect images seem to share filenames with the alleged source materials. They also received a quote from id's Todd Hollenshead, who indicates that if DOOM 3 images have been used, it was without permission, but they have not yet had the opportunity to investigate these allegations. They have not received requested responses from Valve or GSC.