It doesn't really matter they are located. Having them located in the USA makes it much easier, but having them based off shore doesn't mean you can't do anything about them. We've dealt with German, Spanish and Russian sites and have been succesful.

It all comes down to following the money....they all need money to operate. Go after their money sources and/or flood their ISPs with take down notices and legal demand letters. Most ISPs don't want to have to deal with a legal battle, so they will often kick the site off their system after repeat violations.

Once you put the ISP/Host on notice that the site is violating their own TOU/TOS they then become secondarily liable if they don't do anything about it. This is pretty much the same for hosts anywhere in the world. They all pretty much comply with the Berne Convention and honor the DMCA.

But, I have to say that unless the demand letters come from an attorney they do not carry much weight. To be successful the letters must come from an attorney, or they will pretty much be ignored. When they get an letter from an attorney they know you have spent the money and are serious. It's amazing how much faster people respond when the letter comes from an attorney!