Many eBay sellers bemoan the fact that international buyers bid on their items, when the items clearly state that they do not ship internationally. Also, they get upset when a bidder with a minus level feedback wins an item.

On your My eBay, My Account, eBay Preferences page, you can set defaults that will affect your bidders. On this page, scroll to Seller Preferences: Buyer Block Preferences.

Click the link to change your preferences. On the Buyer Block Preferences page, you may indicate who you do not want to be permitted to bid on your items. If any of your bidders fall into that category and attempt to bid, they will see a notice saying they are unable to bid.

International buyers can e-mail you to ask if you'd be willing to ship to them. If you check their feedback, and determine that they know the ropes, you can put their user ID on your Blocked Bidder Exception list and they're free to win your item.