I disagree with banning shoppa, it IS a skillful scheme if played on higher skilled maps, for example, cavern maps.
Put it this way DT, I will use a music related example, I take any #1 chart hit song, which these days is worth alot of money, if I were to change the sound of the main lead, let's say from a "square wave" to a "triangle wave" and try to release the song as my own, it's still the same song, with the same chords/melodies/feeling/theme/etc, I would more than likely get sued, and then trolled by millions of fans of the original song.