Under federal law, you’re required to advertise your product and the terms of the sale honestly and accurately. You’re prohibited from auctioning illegal goods; some auction sites have further prohibitions on sales of other items. If you accept credit card payments from the buyer directly, bill the credit card account only after you’ve shipped the product. Never disclose financial or personal information unless you know why it’s being collected, how it will be used, and how it’ll be safeguarded. Look out for fraudulent checks or money orders.”]
Source: https://www.cuinfosecurity.com/online-auction-safety-part-3-tips-for-sellers-a-745