Yeah, that is something I take a lot of pleasure bringing out when some JW complain about how violant arabs can be in some other countries. I remind them that is is not for us to judge as they are administering, as a country, a justice that once was established by God himself. As JW, we must remain nutral and accept the fact that stoning, decapitating and burning people are methods of execution with God's own seal of aproval!
I also take the time to remind them that the WT also states that a country has the right to capital punishement. Therefore, we realy have nothing to say about it.
I find that when I bring this up, in general, JWs become very uncomfortable and don't know how to handle their emotions.
Sometimes, I add: If you realy want to have a feel for it, you can search for that kind of videos on the internet. It shouldn't be that bad to watch since back in the days, everyone could take part to a stoning.