And back to subject ,I believe the laws (punishment) must be proportional with crime ..(whole my childhood passed in courthouses as family are all lawyers)..
And from my experiences I can say everybody have the possibility of making a crime at any moment if the necessary conditions occur..
if you were born in a different family and different environment its possible...
You're too soft 
Kill 'em all - the world is over-populated. Harsh, but fair 
Obviously, creeping over the speed limit isn't a crime 
Yep, the world is definitely over-populated, but we're already doing our best to solve that, aren't we?
We, the developed and developing nations, are converting the planet's resources to pollution at such a rate that we are going to change the climate, and all the poorer nations are going to be wiped out.
Of course, we mustn't take into consideration the fact that our medical, agricultural, scientific and engineering advances are the main reason why the world population is so high.
So, instead of slaughtering criminals, why don't we employ them to take out all the rich industrialists and research scientists so that we can revert to the civilisation (and population levels) they enjoyed in, for example, 7th Century BC Athens?
You know it makes sense...