Heh. My guess was completely wrong, but (given my background) I should've known the answer!

Here's a hint: The Internet itself has an almost identical vulnerability, of which almost nobody speaks!

Are you threatening me? (Beavis) - YouTube

OK, I was RIGHT! My answer would have been a TINY bit general BUT, if asked to name an ANIMAL, this would likely have been my FIRST guess! I got a big laugh one day when I saw some running across the street in the san fernando valley. After that point, however, they seemed to disappear! WHERE did they go? The power lines!

BTW Most likely cause? NATURE!

SECOND Most likely cause? Stupid and careless humans! I once worked at a job and we suddenly lost power for some time. The cause? A CAR ACCIDENT! Someone hit a powerline pole.

The THIRD one might be POOR DESIGN. A minor problem at one plant could knock out a fair chunk of the country. AGAIN, there HAVE been a few times this has happened.

The fourth one might be PUC stupidity. I'm sure this happens ALL THE TIME. There have been some small cases of it.

Yeah, EMPs, even with all the publicity, are probably a DISTANT TENTH, even with my general categories. Of course SOME EMPs happen by NATURE, and THEY have been known to shut down power, and even fry electronics. THAT is why you have things like heavy duty surge arrestors, etc...

Steve

Not vacuums?

Is it 12 ft tall termites wearing wetsuits running around and crashing into pylons?

It as not really a threat since it was us charging up our space based lasers.

I knew it .