Commons:Lex loci protectionis
Lex loci protectionis is the legal principle in intellectual property law that "the law of the country in which legal protection for the intellectual property is claimed" applies. Although the principle is a longstanding one, the practical application of lex loci protectionis is uncertain within and between countries.
The practical consequence for Commons is that material from country A which may be acceptable to host based on country A's laws (for example, country A consider the work to be in the public domain) may not be acceptable to host based on country B's laws. This matters because infringement under country B's laws may still be actionable, especially for reusers in that country. In principle, Commons might need to consider every country's copyright law! Since this is clearly impractical, Commons:Licensing policy requires material to be either freely licensed or in the public domain in at least the source country and the United States.
In terms of satisfying the Commons:Licensing policy, lex loci protectionis means that the copyright laws of the source country have no relevance in deciding about copyright infringement in the United States. (The exception is where US law explicitly refers to the copyright status of a work elsewhere, for example in deciding URAA restoration of expired copyright.) Application of lex loci means, for example, that in deciding whether a work made and published abroad violates copyright in the US, it is US Freedom of Panorama rules which apply, not the source country's. However, in practice it is unsettled whether and how lex loci protectionis will be applied in real world US legal cases involving freedom-of-panorama elements - see Commons:Freedom_of_panorama#Choice_of_law.
Rule of the shorter term 
Under lex loci protectionis, works from long-copyright country A have a short copyright term in short-copyright country B, but works from country B enjoy long copyright protection in country A. This inequality may be considered unfair. Because of this, some countries provide a partial exception to lex loci protectionis intended to provide for reciprocity between countries' copyright laws. If long-copyright country A uses the en:Rule of the shorter term, works from short-copyright country B will be protected in country A for at most as long as they are protected in country B. This gives the same protection for the country B work within country A as country A work has in country B. However, the rule applies only to the length of protection; all other aspects of protection are still covered by country A's copyright rules.
- Table showing case where rule of shorter term applies (pma = post mortem auctoris, after the death of the author)
|Protection in Country A
(70 years pma)
|Protection in Country A
(70 years pma, rule of shorter term)
|Protection in Country B
(50 years pma)
|Works from Country A||70 years pma||70 years pma||50 years pma|
|Works from Country B||70 years pma||Country B's 50 years pma||50 years pma|
For enforcing Commons:Licensing policy it is important to know that the United States does not use the rule. This means that works can be copyrighted in the US where copyright has expired in the country of origin (see COM:URAA).
For a summary of which countries use the rule, see en:Rule_of_the_shorter_term#Worldwide_situation.
- de:Hundertwasserentscheidung: a German court applied German Freedom of Panorama (FoP) rules for a photograph taken in Austria of an Austrian building and offered for sale in Germany. Austrian FoP covered photographs taken from a private location; German FoP did not. The photograph distributor lost the case, with the court ruling that selling art prints of the photograph in Germany infringed on the copyright of the building.
- Case B 4367-97 (NJA 1998 p. 838): Kalle Hägglund published Mein Kampf in Sweden. Bavaria claimed that the publisher violated Bavaria's copyright. It was found that the copyright in Germany had been inherited by someone and later confiscated by Bavaria. The Supreme Court of Sweden ruled that confiscation isn't a valid method of transferring copyright in Sweden, so Bavaria only confiscated the copyright in Germany and not the copyright in Sweden. The Swedish copyright holder is not the same person as the German copyright holder.
- Explorologist Ltd v. Sapient: Amicus Brief of Google, Inc. et. al. In Support of Defendent's Motion for Summary Judgement illustrates some of the issues in enforcing UK copyright in the US, in the case of a UK video work uploaded by a US citizen from the US to Youtube, and thereby published on the internet from US servers (see summary).
- The Berne Convention has lex loci protectionis provisions in its Article 7(8) (which provides a "rule of the shorter term" except where countries' legislation says otherwise) and Article 16.
- wmf:DMCA Oldenburg (November 2012) and WMF response to it on the application of US freedom of panorama, not source country freedom of panorama, essentially endorsing lex loci protectionis for FOP.
- The Higher Court in Ljubljana, Slovenia, ruled in 2005 that a publisher has to pay a renumeration to the creator of the sculpture exhibited in Međugorje, Croatia, after he has used a photograph of his sculpture in a book. The Slovenian copyright act does not allow for the commercial exploitation of works in public premises, whereas the Croatian act does.