These days, networks are far more likely to be interconnected. On one hand, these networks are more efficient and generally more robust. However, because many are interconnected - McPherson calls that a "flattening of the internet" - when a big one goes down, lots and lots of sites are affected. The results can be far-reaching.
Take the Gmail failure. Not only were the millions of Google users unable to send or receive mail, but users of other systems who needed to send or receive mail from Gmail users were also out of luck. Given businesses' and consumers' dependence on email, that's troubling.
Then there's the issue of adverts. Because Google serves enormous numbers of ads for countless websites, what happens when Google's servers are on the fritz? Ad revenue, of course, would take a big hit. So would performance, as browsers try to load ads from unresponsive servers. And if Google is hit by an uncontrollable malware attack, we're all in trouble.
And what's true of Google is equally true of what McPherson calls "hyper-giants". As recently as five years ago, this wasn't the case. Internet traffic was proportionally distributed across tens of thousands of enterprise-managed websites and servers around the world. But now most content has increasingly migrated to a small number of very large hosting, cloud, and content providers.
More than access and economics may be at stake
The authors of the study don't examine the impact of this concentration on social and political life. But it's not a huge stretch to conclude that a handful of providers now have enormous influence over the internet economy, as well as a good deal of social and political power should they choose to exercise it. I'm not at all sure I like that.