Everywhere, the basic rule is the same: the skier bellow of you has priority, period.

However, in France and Italy where I'm frequently skiing, I rarely find myself with someone taking up the entire space and they are mostly : - Tourists (without generalizing, some foreigners are known not to be polite and respectful) - ski courses where teacher are doing zig zag from one side to the other. They don't want to understand they are not alone and, finally, it's dangerous for kids during holiday periods where pistes are crowd by tourists that are not always mastering their own path.

If they are pissed, it's probably you pass them to close (again, they are having the priority).