We've been AirBNB hosts for 4+ years, and have used AirBNB countless times. At no point in time have we have asked or been required to give our credit card details to an AirBNB host. At check-in, the host asked for our credit card details and wrote them down and stored them insecurely on a piece of paper. They would not let us stay at the AirBNB without providing the credit card details. Terrible experience! Now some company I do not know has my financial details written down somewhere and there's nothing I can do about it...