The principle of territoriality is an internationally valid principle of law which is anchored in civil right as well as in criminal law, according to which all persons and companies, independent of their nationalities, i.e. origin are subject to the legal system of the state, on whose territory they actually stay or operate a business.
With reference to the copyright this in fact means that copyright demands can only individually be protected in the country, in which respective rights have been registered e.g. by the software producer or where these rights exist anyway.
Within the European Union one can start out from the fact that a unique legal situation has been established as the German copyright regulations concerning computer programs are based on the European guideline 91/250/EWG about the copyrights of computer programs. Within the EU the distribution right of the producer is exhausted the very moment the computer program has been put up for sale on the territory of the European Union with the consent of the owner of the rights.