[quote=@MULTI_MEDIA_MAN]
God dammit, we're talking about fictional superhero shit, not ancient mythology!
[/quote]

In the actual mythology anyone could wield Thor's hammer. It was once stolen by a giant who wanted Freyja in trade for it's return.

In the comics the limit is: "Whosoever holds this hammer, if he be worthy, shall possess the power of Thor." The saying is left purposely vague so that it can be interpreted as the writers need it to be. There's no mention of integrity or a willingness to kill anywhere in there.