PK’s in UO were never very effective at deterring unattended resource-gathering (the main ‘cheat’ the staff fought so hard against). I recall having my group of friends all make fishermen at the same time and we reached grandmaster fishing skill in a week or two of 24/7 fishing.
Once we had those characters, there was no stopping us from quickly amassing enough wealth to buy our own castle. It was rather ridiculous. We also ended up with vast numbers of magic weapons and armour, magical reagents, gems, scrolls, and furniture. It ruins the entire economy of the game.
EasyUO was a big part of that. Someone had written a MIB (message in a bottle) script which would decode the coordinates from a bag full of MIBs and allow you to sail to the nearest one to begin fishing it up. It greatlyy streamlined the process of fishing up hundreds of those shipwreck treasure chests!