This is an issue I've grappled with for some time. I've always felt it is appropriate -- to a degree -- to show bad guys doing/saying bad things, thus establishing that they are bad guys. Show they're bad guys, rather than just having someone say they're bad guys. But where's the line between "establishing this character/this group of characters is Bad (and worthy of being trounced by the Heroes)" and "egregiously offensive to some percentage of the audience"?