If a person yells something along those lines, there is usually one of two reasons:

1. You deserved it. Having done something that they did not like and so they decide to say something like that because it has become typical of our society.
2. If it is sudden and for seemingly no reason, assume that the reason behind it is because they are trying to get a rise out of you. Which pretty much works with the majority of the population.

Again, words aren't offensive. People are just uptight.