Web guru Jakob Nielsen risks the wrath of the grammatical bluestockings when he suggests that the passive voice might be useful for headlines, but he’s really talking about front-loading web titles, so that the first two words of a web heading will contain words that will catch the eye of people scanning the page. Since people usually search for concrete nouns, rather than verbs, it makes sense to get those content keywords in a prominent place.

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.

Nielsen got plenty of attention for this claim, but it’s a
bait-and-switch. Passive sentences are not the only way, or even a
particularly good way, of getting subject words to the beginning of web
headings.  Consider “Passive Voice Can Boost ROI in Web Headings,” or “Passive Voice: Surprisingly Useful in Web Headings.” 

Also I cringed at one of Nielsen’s examples of a good, scanning-friendly use of the passive voice: “13 design guidelines for tab controls are all followed by Yahoo
Finance, but usability suffers due to AJAX overkill and difficult
customization.”  If somebody alphabetizes all the page titles on a website, that page is going to be alphabetized under “13.”  

Professional writers know that the most meaningful part of a sentence comes at the end, when you’re setting up for the idea that follows.  So the most significant part of this particular sentence is not that 13 design guidelines for tab controls were followed, but rather that other design choices hurt the site’s usability.