Via The Art of Manliness:

The primary goal in Krav Maga is to neutralize your threat as quickly as possible. This overarching goal governs all the other principles of Krav Maga. Because your aim is to dominate and incapacitate your attacker as soon as possible, pretty much anything goes in Krav Maga. You can’t worry about fighting etiquette when your life is on the line. You do whatever you have to do to preserve your life.