I saw for myself the network snarls that surrounded the iOS 7 release a week ago, and people watching the Internet say the spike in traffic was easy to measure. There are a few hard numbers in this Information Week story:
I was surprised to read that over the five-day period, Apple accounted for only about 13 percent of all Internet traffic — and of course, not all of that, only about three fourths, was for the iOS download. It is not as if traffic doubled (here and there it did, but not on a large scale). This shows that large parts of the Internet are operating much closer to the edge of failure than we would like, considering that big online events like an OS release come along about ten times a year.