While the selection of Hitler as the body for the image may have touched a sore spot with some people, come on... seriously. I'll explain the joke.
Hitler was a dictator. Someone was jokingly referring to Wiz as a dictator. There are other dictators certainly, but replace the face of Mussolini or Castro with Wiz's picture and very very very few people would have gotten the reference.
I understand the issue being touchy to some people, but it's got to be obvious that no one was saying "omg roflcopter!!! Adolph Hitler and what he did was so funny!!!! LOLOLOLLOLOL!!!! omgwtfbbq!" His likeness was merely used to infer that Wiz was a dictator.
Maybe I'm "stupid or young or both" or maybe I'm able to accurately understand peoples' attempts at humor, even when they fall short (which given the relatively low bar set by the sillyness of this thread, I don't think the offending poster did).
I am an American and was affected by 9/11 (not to put it on the same level of the holocaust), but even though it just happened 5 years ago, if someone was raiding Vindi and said "OMG, we dropped him like Al Qaeda dropping the towers" I would have chuckled. Not because I find the original incident funny AT ALL, but because the association drawn is humorous. I think the first sign of healing from a catastrophe is the ability to laugh at references to it when made within the context of a joke.
I mean, heck.. I'm even starting to get over the jokes about my mom and the oval office with Clinton...