Today, any book bought online in England, even one published exclusively in another country, can ostensibly be subject to English libel law. As a result, publishers and booksellers are increasingly concerned about “libel tourism”: foreigners suing other foreigners in England or elsewhere, and using those judgments to intimidate authors in other countries, including the United States.
English libel law places the burden on the defendant to prove the truth of the assertion that's alleged to be defamatory ((see the Times article and Basic UK Libel Law For Idiots)). Given this shifted onus and the multi-jurisdictional (muju for short?) reach of the internet, England becomes the weak spot for any author who writes something about someone that the latter doesn't like — provided, of course, the author (read: publisher) isn't prepared to pay the cost of the grand march to litigation.
The Times story focuses on a book by two American scholars that, in a few footnotes, asserted a connection between a member of the Saudi royal family and the financing of terrorist networks. The publisher — Cambridge University Press, no less! — caved without a wriggle, let alone a struggle: they pulped the copies remaining in warehouses, paid legal fees and damages, and asked librarians to please take the book off the shelves.