How's fault would it be?

[svx_commuter]

I've been wondering, as this is a common practice where I live. I am driving down the road, a two lane road, and there is a car or truck standing at the side of the other lane. Oh it's making a delivery or letting someone off or picking up someone. All perfectly legal. The cars approaching me and the standing vechicle from behind moves into my lane to pass the standing vechicle, at least two feet into my lane. The people in front of me move to the right to allow the approaching cars to pass.

Now lets say I am not being real observant and hit one of these cars that is in my lane. Who's fault would that be?

Now let's say I am following the cars in front of me that are passing a vechicle standing at the side of the road and hit one the cars in other lane because I moved into that lane and the person did not move over to allow me access to pass the standing vechicle. Who's fault is that?

(This did not happen to me. I have just been wondering about it and I do not know anyone that it has happened to.)