Chesterton's Fence
G.K. Chesterton, author of The Man Who Was Thursday, one of my favorite books, is mostly remembered in some circles for his thoughts on fences:
If you see a fence in the middle of a road and you can't think of a reason why that fence is there, DO NOT REMOVE THE FENCE.
Once you understand why the fence was there, only then can you remove the fence.
People generally aren't in the habit of building things for no reason. Sometimes, that reason can disappear, and we're following an outdated pattern for no reason. That is, maybe there used to be a horse form here, but the horses have all moved away, and no one bothered to take down the last piece of fencing.
Once you understand that, only then should you think about removing it.
Aside
A podcast I used to listen to (I Don't Like Mondays) used to regularly tell the story of seeing a sign saying "Please don't feed the horse" around an empty field where there was no horse. The host jokes that he's been fearful ever since that he might accidentally be feeding the invisible horse right now
See Also
The Monkeys and the Ladder
Width of a Road
Width of the Space Shuttle
The Libertarian Bear Problem