Konami has revealed that MGS4 lacked the series' iconic theme due to claims of plagiarism involving a Russian composition from the 1970s. Metal Gear composer Norihikio Hibino (who didn't write the theme) doesn't seem to think that's true at all.
GameCyte has pulled several clips from the Russian composition which best match up against the MGS theme. Is it really a case of plagiarism, or is it a more likely case of inspiration? Listen and decide for yourself.