Nielsen's thesis is that the passive voice -- which is usually frowned upon by people who love good prose -- enables headline writers to "front-load" their heds with the key concepts from the story, making it easier for people scanning those headlines (as search results or feed headlines) to pick out their meaning more quickly.
However, recent findings from our eyetracking research emphasized the overwhelming importance of getting the first 2 words right, since that's often all users see when they scan Web pages. Given this, we have to bend the writing guidelines a bit, especially for elements that users fixate on when they scan – that is, headlines, subheads, summaries, captions, hypertext links, and bulleted lists.Link
Words are usually the main moneymakers on a website. Selecting the first 2 words for your page titles is probably the highest-impact ROI-boosting design decision you make in a Web project. Front-loading important keywords trumps most other design considerations.
Writing the first 2 words of summaries runs a close second. Here, too, you might want to succumb to passive voice if it lets you pull key terms into the lead.
Design critique of Jakob Nielsen
Jakob Nielsen consisely summarizes all the reasons that reading PDFs on-screen sucks.
Jakob Nielsen AlertBox on designing the PR section of your Website to make journos happy
Nielsen's top-10 blog usability mistakes
Nielsen: User-education won't fix security
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.