*Unlike previous games, casting this spell on a non-hostile target in public is considered an assault, so you can't use it to easily murder someone in front of witnesses. However, if you are hidden when you cast the spell and nobody sees or hears you, you can still get away with it. Though if all of your witnesses are within the range of the spell, there may be nobody left to report it even if you are seen.
*A more common use for this is to cast it on a group of enemies, so they all fight eachother instead of you. Odds are you'll be left with just one last severely weakened enemy standing, which you can then mop up on your own.