For someone who depends on the Internet for many things (assuming my mom will stop calling and just instant message me), it is definitely easy to get freaked out when my connection goes down. I usually run a few tests and check a couple of different websites, just in case it's only one server out there (perhaps my email) instead of a complete outage.
While the problem is usually rectified within minutes (rebooting my computer, resetting my modem or a router), it's not usually a happy moment. But for others who have experienced similar things, they compare the nature of using the Internet constantly to an anxiety disorder.
Hmm, I don't think I would quite go that far, but I can believe people could get really freaked out in a situation like that. Then again, there are already plenty of disorders out there to accommodate, which is why I find it strange to narrow one specifically to the Internet. If the power goes out, and you are channel surfing, do you become anxious? In those tense moments, grab a candle and a book or if your computer has battery power, there's always Solitaire.