There were some exploits in The Witcher 3 that let people harvest hides and pearls for gold. If you used them to make a quick buck, well, the game's developers know. And they're sending someone after you.
WhatsMyGame posted this video today from his playthrough of the new expansion, Hearts of Stone, and it shows his travels being interrupted by an in-game tax collector. Who knows all about your undeclared income, where you got it and how you did it.
Killed cows around White Orchard? He knows.
Stocked up on pearls? He knows.
And he knows, better than anyone in Temeria, the punishment for your crimes.
Before you go panicking (there's a hefty fine!), know that his final judgement isn't set in stone. He actually asks you if you're guilty of the crimes you're being accused of.
If you say no — regardless of whether you actually did it or not — you don't just get off scott free, you're given a reward for your "honesty".
What a neat touch! Other studios would crack down on this sort of stuff, with rushed patches and tersely-worded forum posts. CD Projekt Red? They send in cow armies and joke taxmen. You can see the full exchange below.