While the MLK quote may be wrong, I feel this Mark Twain one fitting as well: "I've never wished a man dead, but I have read some obituaries with great pleasure."
To anyone saying we shouldn't feel sorry for the guy and rejoice - I think you're missing the point. I doubt many (especially in the US) feel bad for the guy. But the celebration shows a clear lack of perspective, as we don't even know what his death means in the scheme of things. Plus, it's just in poor taste anyways and just adds to the American stereotype.