19 clicks is a surprisingly high number. I thought it would be less. BT Research Laboratories (who I find out are now called "Adastral Park" (this is the lab that had a patent for hyperlinking)) had said that everything should be connected by no more than 6 clicks. (Although I'm unable to find a reference for that now.)

The article doesn't mention what the average click number is. I'm curious what kind of pages are so deeply nested, and what proportion of pages are buried so deep.

> This arrangement, though, reveals cybersecurity risks. Barabási writes that knocking out a relatively small number of the crucial nodes that connect the web could isolate various pages and make it impossible to move from one to another. Of course, these vital nodes are among the most robustly protected parts of the web, but the findings still underline the significance of a few key pages.

Well, maybe. I assume all sites (except those knocked out) would still be directly accessible?