Just 10 days ago, Vivek wrote Anon 101: An Introduction to Anonymity on the Web. In the section on those who assume two different identities, at least one of which is anonymous, he wrote:
Do not make the mistake of maintaining two blogs/avatars: one with your real identity and the other anonymous. [...] It requires a lot of effort and skill to maintain two identities, if only online. You would require two completely different styles of writing. [...] You would also need to write posts on different topics, or else to use completely different phraseology for your posts. [...] Remember, it just takes a momentary lapse for the manure to hit the fan.
[Daniel Lyons' forthcoming] book, in part, led to [his] unmasking. Last year, his agent showed the manuscript to several book publishers and told them the anonymous author was a published novelist and writer for a major business magazine. The New York Times found Mr. Lyons by looking for writers who fit those two criteria, and then by comparing the writing of “Fake Steve” to a blog Mr. Lyons writes in his own name, called Floating Point (floatingpoint.wordpress.com).