While this may be true, this also doesn't always hold. I was treasurer for a student union and if people signed for it, we would take the money directly out of their bank account ("automatische incasso", very normal over here). Doing this requires a contract with a given limit and number of transactions. I tried to get the limit raised, but they refused, so I just went over the limit and no one ever ever complained. Had no chargebacks, but still, doesn't seem like a very safe situation.