^It does but I think more buyers adhere to the shipping information provided in the listing. if the listing does not even include international delivery information, quote etc. it should be clear i think.
the buyer then purchases at their own risk no matter how they intend to game the system, or buy without any integrity.
I believe the default ship-to is "worldwide" and anywhere you haven't specified a shipping cost to gets a message like "contact the seller for shipping costs to your location" -- lots of smaller U.S. sellers don't specify shipping to Canada and it's not always clear whether they are willing to ship here or not, which can become an issue with last-minute discoveries and bids.
I state clearly in all my listings that I do not ship outside Canada/U.S.A. and that buyers from anywhere else, even UK, should message me before bidding. Until now I wasn't actively blocking buyers based on location, though.
I wish you could specify a minimum feedback level (I'd pick 3-5) but I can see how that would discourage new users/buyers.