There was an interesting base project wherein the true coordinates were only known to the top leaders. All other builders connected through a custom client that offset the coordinates to hide the true location. If anyone became untrusted, they were simply blocked from the client and could not expose the coordinates. There was care taken to ensure the area outside the proxy was never shown, block place directions were randomized to prevent reversing the proxy, etc.

The base apparently thrived for months or years before finally being discovered and destroyed.

It's all based on the seed and coordinates.