to the attention of everyone dining-in. Check your bill! it happened to me, that they managed to add "by mistake" a small drink(2,5€), which I haven't ordered. Judging by their reaction upon my reclamation, it was not a mistake, but a premeditated systemic fraud. They simply offered me some direct cash from their tip box, without explanation and they quickly destroyed the evidence of fraud. On the top of that, they offered me two different bogus explanations on why this could happen.
The fact that they compensated me from the tip box makes an impression that in the time of plastic money there are less tips, so putting additional items "by accident" is a way to get tipped. And the speed with which they did that further proofs this assumption.