Encountered another player at my base

So I was coming back from the Anomoly and landed at my base to find another player there. This was my first encounter with another player outside the Anomoly so I was pretty excited, but this other player pretty much completely ignored me before vanishing in front of my eyes. My "base" right now consists of only a base computer, a couple solar panels, a couple batteries, and a teleporter. The weird part is that these items were still wired up, but nothing was working and there was no power to anything. I essentially had to delete and rebuild these items to make them work again. I have my network settings locked down so no one can mess with my base. Does anyone have any idea what could have happened?