it's indeed breaching international copyright laws. if you'd play by the rule/law you couldn't even take a cd legally to other countries. the reason behind it is the way record companies license their music. major record companies don't work as globally as it may seem. and no, you can purchase a gift certificate in one country and use it in another... as long as you have a residence/address in the country the certificate came from. so far it is possible to use more than one account in itunes.
Examples of Apple Putting the Customer Second