Developer Tim Cotten has shared a blog post called "That Time We Burned Down Players’ Houses in Ultima Online”. In the post, which he decided to share after the game recently marked its 25th anniversary, tells the story of how Ultima Online was being plagued by item duping, and how the game didn't initially have a way to deal with them.
First coming to Ultima Online as a player, Cotten tells the story of knowing that players were duping items, but it wasn't always obvious how. It was also not always common for players to report what was going on either.
Players were able to abuse areaserv boundaries, because there wasn't one seamless server. Some players observed that if they worked with someone else, they could bring an item on one side of a laggy border and pick it up, handing it over as both players were crossing meant the item would now be duplicated and both players would have it in their possession. Item duping is still a problem that still affects modern MMORPGs, only now there are more ways to fight it and clean up the damage. In much less showy and memorable ways, however.
Cotten joined the team and saw that UO didn't have a database. Each shard was reliant on a shutdown and backup sequence sometime overnight. The backups and state of each areaserv went into a large backup file, so there wasn't a way to look into player possessions or objects. One thing he did was request a hashing function. Once the code was updated, after a few weeks spent tagging duped items, a plan was set into motion.
Because it was the early days, they turned duping ring fighting into an event. an event that led to player's houses being burned down. And that was just the beginning. Speculation was rampant too.
It's a really fun story that gives a peek into how things were for the community as well as behind the scenes on a game that now has 25 years of history behind it.