Some jackass breaks into your home and steals a bunch of items. Balance-wise it should be difficult to do if you upgrade your own home (guards, security, magic traps, etc), but when someone is successful the homeowner is pissed. Have the person flagged (invisibly obv) for stealing crap (unless a guard sees them, etc), and have NPCs in the underworld, or simply NPCs that your character has good enough faction with, be able to act on those flags and if you go out talking to your sources, maybe you get a quest or a contact so that you can do something in return. So maybe that Redguard woman in the skooma den that you have good faction with might be able to give you some intel or a name or maybe even a quest. Maybe you can find out whereTHEIRhouse is at, or put a contract out on them, or track them down in the gameworld for vengeance, maybe even try ganking them in some far off dungeon and tee-bagging their corpse for forum screenshots. This could easily work like the intel or whatever agents in EVE, just make it deeper than having to go see an "Intel" agent.