It means that when an Athiest kills, he/she accepts that they are solely responsible for their actions unlike many crusading god worshipping zealots.

Bush has stated publicly that God supports his war in Iraq, he is blaming god for his crimes.

If Athiests dislike a person or want someone elses property they have no book telling them it is OK to steal or murder as they are special and just doing Gods work. Athiests must accept that when they murder they become murderers not crusaders, when they steal like Israels Jews and Americas christians do they recognise themselves as thieves and not chosen ones doing gods bidding.