One of the great unanswered questions of online media law is where one can be sued for libel or defamation.

Say you are writing about someone in London from a coffee shop in Sydney to a blog hosted on a server in San Francisco and someone in Berlin downloads and reads the post. What court might hear the Londoner’s libel complaint?

Different countries have different laws about how libel and defamation works, so there is no single answer to this question. Consequentially, there has been some concern that this could lead to forum shopping — claimants looking for the most advantagious jurisdiction for launching a libel action against someone in a different part of the world.

In countries that have British-style libel law, for example, all that traditionally matters is where something is published or widely accessible. Late last year, Dow Jones settled a suit that suggested that Australian courts could claim jurisdiction over anything accessible Down Under.

Another case that was being closely watched was a Canadian lawsuit against the Washington Post over articles on its US-based web site.

The outcome there will lead online publishers and bloggers to breath a sigh of relief. An Ontario court of appeal this week decided that Canadian courts do not have unlimited jurisdiction over foreign web sites, reversing a lower court’s decision to hear the case.