Napster was shutdown by a court in the country in which it operated.
Which also happens to be the country in which Slashdot operates.
Likewise just because one judge in the UK made one decision doesn't make the software illegal in any other parts of the world.
Both the USA and Great Britain agree about the illegality of a copying service with no substantial non-infringing use. What makes you think courts in other countries that have signed the same copyright treaty won't reach the same conclusion when the MPA (the MPAA's foreign division) goes into those countries?