Backhoe, n. <bak-ho>. A massive, piloted machine/vehicle used for excavation. It has a large bucket and uses this to dig.

This story was related to me during the Sendmail tutorial at LISA 99 in Seattle, Washington, USA. During his tutorial, Eric Allman told us the following (my apologies for how badly I'm probably messing it up):

Once upon a time, on the Berkeley campus, there was an earthquake. Just prior to this earthquake, a backhoe cut through the only link connecting Berkeley to the outside world. Because of the earthquake, the workers were unwilling to get back in the trench to figure out the extent of the damage. So the fibre break went unfixed for three days.
Did I say this was the only link to the outside world? Not quite. You see, routers have evolved to become almost sentient. When they discover that a link is down, they immediately begin sniffing (here, he sniffs around in the air) to find a new route. What did they find? Lo and behold, a professor's home PC was connected to the campus network via an ISDN connection, and was coincidentally networked to his wife's PC, which had a dial-up account with a local ISP. The routers then begin to send all of Berkeley's traffic through this (33.6? 56k?) modem connection. So, for these three days, Berkeley is connected through this insane route.

The moral of the story is then this: Backhoes are the only known natural enemy of fibre.