I think you guys are all being pretty unfair to op - I don't think she thinks that she has a divine right to unimpeded progress and the various other things that have been said throughout here. She's admitted she was surprised to find herself so irritated.

And it's pretty clear that there are extenuating circumstances beyond how to safely descend down a hill in this case - if you're riding laps on a 1 lane private hill there really isn't a way to do it safely and not to annoy all the people that live in that neighborhood. Any car going up or down that hill would be giving way and going into the pullouts as is safe. And I doubt op would have a problem with the cyclist taking the lane if it was a larger road in general.

So if she's descending down this 1 lane road and there is a car going up this one lane road... Should the cyclist just stick in the middle of the road because that's her right and the car doesnt have a divine right to unimpeded progress?

So we can all agree that taking the lane is often the safest way to descend, but can we all agree that perhaps the cyclist in this case would be a lot safer in general if she were riding laps on a different hill?

In general when I'm riding, I'm very aware that cars are 80 times bigger than me and quite capable of killing me. I often wave cars that are hovering behind me to pass me, because I don't want them behind me. If I see any cars coming behind me when I am about to descend down a hill that I know I need to take the lane for, I generally stop at the top, wait for them to pass me and then descend. That's because I don't want a car behind me if for some reason I wipe out and I'm splat across the road, because being splat + run over is worse than just being splat. I do take the lane when it's necessary for my safety, however, I don't take the lane just to teach cars a lesson that it's not just their road or whatever.