Murdering Hitler, for example, could have been quite a public service to Germany (and the world) anywhere from the 1920's on...although it would still have been, technically speaking, a crime according to German civil law.

Stealing food to save the life of a starving person could also be justifiable.

There are any number of examples one could come up with, but it doesn't change the fact that we all think that murder and stealing are (normally speaking) morally quite wrong.

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Now, stealing horses was considered a glorious and commendable act among the Indians of the western plains...an act to be proud of...provided you didn't steal the horses from a fellow member of your own tribe!

Tricky business, isn't it? ;-) Those Indians were not moral relativists, they just had a different set of customs, that's all.