You put Facebook as the most important on that list? I'm not trying to say it wouldn't severely impact people if Facebook were down for a day, but I can't imagine not being able to use google or wikipedia for a day. This would definitely result in many failures of time-dependent projects.

I do agree with you completely, but to play devil's advocate:

- Youtube down, go on another video site or wait a day, who cares

- Google down, use bing/yahoo

- Wikipedia down, can likely find content in a cache (less easy but often very doable if Google is also down), if not the majority of Wikipedia users could wait a day and not have it do much harm. I use Wikipedia daily, but if I had to go a single day without it, it wouldn't really have a negative impact on me, just be slightly annoying. Or, find information on other sites, books, etc.

- Facebook down, there's no alternative. You can't just move over to Diaspora for a day. This is the only one where it being down for a day means you lose that functionality completely for a day.

When Facebook's down, I use GMail. Or G+. Or LiveJournal. Or my Amherst-only social network. Or text messages. Or call my friends up on the phone, or talk to them at work, or walk over to their apartment and knock on their door.

Do people really only have one communications media? I find that with anyone that I actually talk to on a regular basis, I talk to regularly on at least 3 different communications media, often simultaneously. (I'm pretty fond of taking Facebook conversations offline to text message when I need to say something private, for instance, or to GChat when I want something a little more real-time.)

I'm no expert on this subject since I haven't had a Facebook account since a few years ago, but I would imagine there are certainly some people/scenarios where something that Facebook would normally be used for couldn't be done elsewhere. Like uploading some photos. Or looking at old photos. Or messaging someone who you don't know well enough to have ever bothered getting a phone number / email from because Facebook was good enough for talking to them.

Surely not being able to look at an old photo wouldn't result in a failure of a time-dependent project.

And if an important project would depend on somebody, you would probably bother to get a phone number or an email.

As I see it, disabling facebook for a day would be much less inconveniencing than say, disabling google's search engine (of course you could use alternative search engines, but none of them come close to google's result), or wikipedia (to which there's not much alternatives, really).