Depends on how the sale was handled - did you send an invoice or did the customer purchase via your web site or via eBay ??
As we don't have all the details of your transaction. Here's a few ways that you can protect yourself - for example you can require a confirmed address meaning both the shipping and billing address must be the same. You can accept payments from only US PayPal Accounts. You can block eCheck payments (except from eBay). Make sure that the item or items you sell can be shipped, tracked and insured if applicable. You can limit your shipping to only domestic US Addresses.
