Technology that provides a platform for Internet users to express their views on a range of topics has proliferated over the past several years. Many of these technologies, such as financial message boards, blogs, social networking websites and e-mail, allow users, or “posters,” to express themselves anonymously by using pseudonyms traceable only through the hosts of the sites or their Internet service providers. As such speech has increased, so to have actions against Internet-based companies—such as Yahoo!, Facebook, Twitter and Microsoft—seeking to discover the identity of someone who posted allegedly defamatory material. But courts have adopted a standard that creates...