A command bug with the /kill command (More info in description/environment)

So, basically, it has to do with the /kill command. I was trying to figure out how to kill an item that is specifically a chest, and no other items (which by the way, I failed at ) Anyways, I used the command /kill @e[type=Item] and that killed all items as expected. But, after that, I added a space and some other text, and it was kind of like a testfor command. Basically, if whatever is in the argument brackets is true, then it will kill the player who did the command. Here's an example. If I did
/kill @e[type=Pig] InsertAnyTextHere
then if there was a pig in the world, I would die. And if I did
/kill @e[type=Pig,name=Barney] InsertWhateverTextYouWantOverHere
then if there was a pig in the world that has a custom name of Barney, I would die again. It could really be used to map maker's advantage, but it's a bug that should be fixed. Thanks dudes!