Never, and I never saw it either. Only once I heard from a not so exemplarly brother that worldly people were the dead men walking, and it was quite shocking.
They hate "the world" as a whole, not the individuals living in it, and they also look down on witnesses doing something they dissaprove of, like starting a relationship with a worldly person, dressing worldly or displaying any other worldly behaviour.
Not mixing with the world can be missundertstood as contempt but it's not. They truly want to help those people they keep their distance from.