The article reviews several books on Adobe Photoshop, including "Photoshop CS2 for Dummies," by Peter Bauer, "Adobe Photoshop CS2 Studio Techniques," by Ben Willmore and "Photoshop for Windows and Macintosh: Visual Quickstart Guide for CS2," by Elaine Weinmann and Peter Lourekas.

The shutdown does not appear to be a spontaneous event, given that the Telecom Egypt, Raya, Link Egypt, Etisalat Misr and Internet Egypt ISPs each shut down its part of Egypt's Internet in sequence an average of about three minutes apart, according to Manchester, N.H.-based network security firm Renesys Corp. This sequencing indicates that each of the ISPs may have received a phone call telling them to drop Internet access to their subscribers, as opposed to an automated system that kicked in to take down all of the providers at once, Jim Cowie, Renesys chief technology officer and co-founder, blogged on Friday.

If this analysis is correct, it indicates a level of governmental Internet control unseen to this point, not even in China, Iran and Tunisia, which have been accused of manipulating Internet access to quell government opposition. Scientific American spoke with Cowie, whose company monitors global Internet infrastructure, to better understand how it works under both normal and, in this instance, abnormal conditions.

On January 27, we observed hundreds of providers all over the world suddenly telling us that most of the network addresses in Egypt no longer existed. It's not that their paths were changing a little bit to get better value out of their connection or engineering around a little cable break or something. It was really a matter of just disappearing. And it was just Egypt—you didn't see networks in the Gulf, India or China go down, as you might if a submerged cable in that region had been damaged.