Gratuitous or unprovoked meanness just doesn't sit well with me. Comedy at the expense of someone who really doesn't deserve it takes the funny element out of it.
"Borat" was a classic example. The world laughed and praised this guy who turned a struggling country and its people into the laughing stock of the world. Who the hell knew anything about Kazakhstan before Sacha Baron Cohen found this novel way of making himself rich by pretending to be from there and singlehandedly attributing the worst, unfounded stereotypes you can imagine to them? You can picture the scenario when a mostly uninformed American, who watched "Borat," encounters a Kazakhstani student at a bar. Embarrassing.
The more recent movie that comes to mind is "Walk Hard." All I needed to see was one trailer to be utterly disgusted. Although I'm a fan of John C. Reilly and I get the whole Johnny Cash/Jim Morrison/etc. parody, some stuff is just sacred and unnecessary. Of all the material to chose from in Cash's life (and, admittedly, there was plenty to mock, even though I am a diehard fan), they chose to mock the tragic death of Cash's older brother Jack who died in a power saw accident when he was only 12 (I believe). The movie trailer shows a kid learning to play a guitar and singing something stupid like, "I cut my brother in half" or some crap like that. WTF!