As Tnxd said, generally a compound (or any bow that generates decent velocity) will punch its arrow clean thru...well just about anything...unless you hit a very solid bone square, or have the shaft break which is odd, but not unheard of, especially with people shooting undersized arrows. My issue with bow hunting is that its alot like pistol hunting, in that it takes more......dedication? skill? restraint?, not exactly the words i want, to be fair and humane. With an arrow you kill by stabing your target ONCE, it dosent generate the shock trauma or even the wound channel a bullet does. A good shot will very rarely drop an animal on the spot, but more often then not requires patience to wait for the animal to die and a decent ablity to track. I bow hunt, but im neither sneaky enough, nor patient enough to get many shots ill even consider taking. As a result i shoot very few animals, not that it maters as there is no hunting seasons here.
On a side note, where i lived growing up there was a lot of poaching at night, as well as semi-legal hunting during the day. My friend and I killed a number of deer with bullets still in them, and we found quite a few carcasses that i would be willing to bet were killed and lost by rifle hunters. Poor ethics, and decisions can be made by all.