I have no problem with any racial group, I don't like to generalize because there's good and bad in any group of people. Further to what Tinman said, I live in the trashier end of St Kilda and some of the white trash around my streets is far worse than the multicultural populations from other areas that have a worse reputation. I also agree with Dreamy that if you don't like somewhere or don't like their way of life or values or feel a need to clash with it - then fuck off.
I know the Lebanese & Sudanese communities are two that over the past few years have had alot of problems. For example in Melbourne there's been a number of incidents with Sudanese around the Noble Park/Dandenong area in the last year, as well as some big brawl in Marybyrnong & a couple of incidents out in Melton I think too. And Sydney has seen most of the Lebanese related incidents. But I think it's unfair to generalize those entire groups, because for every Lebanese or Sudanese person who doesn't want to make an effort to adapt, there is another who is making a great effort, respecting everyone as they wish to be respected themselves, and making the best of their situation. Those people shouldn't be victimized or treated badly because of the bad seeds they get unfairly associated with.
So just the ones who are making it harder for the good seeds in their community by causing trouble can fuck off, and need to look at the impact of their actions on their own community. I know it's harder for those groups in particular to adapt, as they have come from places with VERY different values to Australia and haven't come as voluntarily as other immigrants either, they are escaping conflict rather than choosing that Australia is where they want to live. But those who don't want to make the effort still should be grateful to be in the most liveable country in the world rather than a third world or war-torn country like they came from.