At first I thought it was just a simple bug that would mark anything you put into someone's "owned" backpack and then transferred (I.E. moved, either by clicking and dragging or by right clicking and choosing "move to *insert character*) to another character as stolen, but then it happened to random things that I transferred between inventories. Then it happened to things not marked as stolen, but that were originally equipped by another character, and then equipped to a different character. Now the bug has truly transformed into a virus. I just equipped a weapon from one character's inventory to a different character, and all of the equippee's equipped items have been marked as stolen, including the newly equipped item and the item that it was replacing.