Given the transmission by retweeting, it would be interesting to see how the networks of followers facilitated or impeded its spread. There are many hub individuals with hundreds or thousands of followers. But the most widely followed may not themselves do much reading of tweets, and so may not have been very susceptible to spreading the virus. Smaller networks of frequent readers and retweeters would be better vectors. Still, eventually this bug got to the big twits:
On Twitter, the spread of the worm to a highly connected person or people may have been enough to tip infection rates over that threshold and allow it to break out into the wider world. It may not be a coincidence that around the time the second peak was building Sarah Brown was infected, retweeting the bug to her 1.1m followers like a virtual Typhoid Mary.