There was a server once where I joined at the tail end of it's lifespan, when most of the bases were abandoned. There was an in-game physical currency system which you could use to purchase things from player-ran shops, however fast amounts of money were stored away in chests buried within the bases, often inaccessible because there was a claiming system that let you lock down doorways.
In spite of the server banning theft, I quickly became an adventurer who sought out abandoned bases, broke into them through side entrances, gaps for ender pearls, and so on to steal money (and anything else interesting) before taking it back to my own fortress, selling valuable items, keeping what I wanted, and getting very very rich.
In spite of it feeling morally questionable it felt kind of sick. Exploring abandoned structures and looting valuables, trying to piece together the history of the bases as I went along. There was always this unshakable feeling of being in the ruins of a greater world, scavenging detritus to build meager monuments amidst titanic remnants of ancient glories. At least I was getting paid.
