In honor of Protean, here is a long unedited post.

Kidding. But these are my disjointed thoughts. I know I need to befriend brevity (well it's not happening tonight, kids!!!)
1) As Alean pointed out, if you identify or empathize with the 'napalmed girl' -- who has a name btw
Phan Thi Kim Phuc - then it's not funny. FineLine also touched on the importance of identification -- what's humorous is sometimes a matter of degrees in your relationship with the subject. It may be alright for you to joke about the passing of your parents, but if someone else were to crack a joke (while you're in mourning), I'm sure your response would not be the same. 'Ownership' is another way of looking at it (ah gawd, I hear the comics frothing at the mouth already)
2) Fineline even mentioned it 'cheap shots' -- some humor is just easy. It's not edgy, not deep, it's cliched, lazy, and therefore not funny. Violating boundaries to comedic effect and more importantly
to make social commentary funny (which is really what 'humor with a point' is) is hard, I know 'cause I actually do it sometimes, nnkay? (Yeah that's right, I'm all that.

) I think an example of morbid or twisted humor as social commentary (or vice versa) that works is '
TheTruth' anti-smoking campaign.
[Long rant about how just because it's offensive, morbid, "twisted", or "sick' doesn't make it some genius piece of art or even funny.]
4) All twisted/morbid humor is not the same, intent, the social commentary, the POV, that pretty much makes it or breaks it. Look at public figures in the states who are known for such humor - Bill Maher, Margaret Cho, Kathy Griffin, Eminem -- they don't share the same opinions or stances but they do use 'shock and awe' humor that plays with boundaries and expectations of decency and propriety. *Edit* And what you find funny often hinges on how much do you agree with it.
5) However, in the cases of 'deep' or 'sarcastic' pictures like the Mickey D's one, I really wonder who made it. Was it Vietnamese refugee? Was it a guilt ridden heir to the McDonald's fortune? Some bored blue-blooded 6th year Hampshire student who got high one night and had a lot of time on his hands? Similar to intent, I think the overall context depends a lot on who made it. And effect overrides good intentions.
6) Does it matter I did
not find the Mickey D does Napalm pic funny? 'Cause I did (or maybe grammatically I should say 'did not'). I hold commentary on it until I figured out who made it and in what context.
7)BTW, I use 'sick/twisted/wrong' etc. humor myself. Except when I do it,
it's funny Hahahahaha -->it's a joke people.

Jeez, how come no one has a sense of humor.
6) That's right I'm not done yet, I'm gonna keep rambling tomorrow.
*Edit*
7) Never mind I think everyone else covered my points already. Sheesh. Okay I'm gonna find examples of 'wrong' humor that I find funny.