In other words, people are increasingly going to Facebook through their mobile devices, which reflects a general shift toward accessing content through smartphones and tablets. The problem is that advertising on those devices is harder to sell because it is harder to display. Equally important, it’s harder to integrate if you don’t control the mobile devices’ operating systems. And the operating systems that control the most important of those devices—Android and iOs—are controlled by Facebook’s key rivals: Google and Apple. The New York Times had a good story Monday on the general challenge of selling advertising on mobile devices that keys off of this Facebook disclosure in its IPO, but it seems there’s a good story out there for whoever can scope out if and how Google and Apple could and might take advantage of Facebook’s vulnerability.

4. Facebook and litigation:

Another part of the “risks” section says:

We are involved in numerous class action lawsuits and other litigation matters that are expensive and time consuming, and, if resolved adversely, could harm our business, financial condition, or results of operations. In addition to intellectual property claims, [these suits include] numerous other lawsuits, including putative class action lawsuits brought by users and advertisers, many of which claim statutory damages, and we anticipate that we will continue to be a target for numerous lawsuits in the future.

The prospectus goes on to say that the company doesn’t believe that any of these suits will result in material losses, and it’s true that any large, successful company is the target of all kinds of attacks from plaintiffs’ lawyers. Still, someone ought to do a story homing in on the cases that are potentially most threatening, telling us what they’re about and what the consequences, if any, might be. Are they real, or do they simply illustrate abuses of the plaintiffs’ bar?

Steven Brill , the author of Class Warfare: Inside the Fight To Fix America’s Schools, has written for magazines including New York, The New Yorker, Time, Harper's, and The New York Times Magazine. He founded and ran Court TV, The American Lawyer magazine, ten regional legal newspapers, and Brill's Content magazine. He also teaches journalism at Yale, where he founded the Yale Journalism Initiative.