If you are trying to reach Facebook today, and finding Facebook gone, it may be that Facebook is down. Or it may be that part of their Internet backbone is not routing traffic to them. As we write this, it seems to be a bit of both: Facebook is down for us, because part of their Internet infrastructure is hosed. Here’s a detailed explanation of how your computer gets to the Facebook website and, at the end, a work-around if you are currently unable to reach Facebook.