Comedic or Offensive?

One of the latest videos to go viral is one of Sacha Baron Cohen knocking over an old lady at the Britannia Awards this year.

http://www.youtube.com/watch?v=sQrG8fBtH-c

While some people found this video to be quite entertaining, there were many others that found it offensive.  Strange thing about comedy is that most material may be deemed offensive by some.  For instance, I laugh when comedians talk about their own personal lives, but it's not so funny to me when they make fun of those with asthma, as I have lived with asthma all my life and I've seen my family members hospitalized from its effects.  However, I've learned to overlook those kinds of jokes as just an ignorant display and continue to laugh at what I do find funny.

As a "larger than some" woman, I don't particularly find jokes funny when a small person makes fun of a big one.  Conversely, neither do I think it's funny when a big person makes fun of small people.

I think jokes come across funnier when the comedian comes across as making fun of his own faults rather than intentionally offending another person for the sake of laughter. What do you think?  Is all fair in love, war, and comedy; or are some things simply out of line? Do some comedians go too far for the sake of a chuckle?