Here are some random brief points off the top of my head that may or may not be pertinent (your essay definitely needs to be longer)
- Recent media story: Gordon Ramsay. His language shocks, offends and incites emotion > Senate inquiry > However, it peaked at 1.6 million viewers nationally, so it obviously doesn't offend everyone
- (this was one of the topics on the exam last year). Apparently, many students mentioned the Chaser's eulogy song, which massively offended, so it would've been good to talk about, and was super-recent at the exam time
- discriminatory language offends, including negative + gratuitous labelling, stereotypes, etc.
- negative labelling example: (2007) a man was fined for yelling "Go Nazis" to a Jewish man; prejudice not tolerated in Australian society.
- offending through pronouns/false generics
- Sue Butler, editor of the Macquarie Dictionary, argues that the word "fat" causes more social ripples than swearing
Etc. Make sure you have real examples to back everything up.
EDIT: Oh yeah, check last year's assessment report. Starting from the end of page 7, it has samples, and other ideas of what you should've talked about:
http://www.vcaa.vic.edu.au/vce/studies/englishlanguage/assessreports/2007/englang_assessrep_07.pdf