Ive had a nightmare selling a few old phones on ebay.
I use the "only allow bidders from countries I ship to feature" but still get Nigerian scammers all the time. They manage to register with UK addresses and bid on loadsa stuff. I had a buy now on a phone and it was bought a relisted 3 times in 24 hours due to these!!!
Ebay seem to shut their accounts within hours of them registering but its too late by then. They refund your final value fee but not your listing fee.
They need to stop these idiots being able to sign up with UK addresess.