i worked at NG for 7 years, and there were several instances (the last one being in 2010) where email system company-wide was crippled or knocked offline by an email that was sent to the wrong mailing list. apparently, there was one available that included literally every single person in the system (probably about 100,000 people).
i remember one morning in about 2008 or so, getting an email addressed to some team i wasn't a part of, seeing the "CC" list was several miles long, and i knew instantly what was going to happen. i guess the "first post" instinct in me acted up for the first time ever. i knew we were all already doomed, so i hit reply-all and simply posted: "oh no, not again." i did manage to be first, but before i could blink, i had over a thousand new emails all saying some variation of "WHAT IS THIS?" "REMOVE ME FROM THIS LIST" and "STOP REPLYING FOR GODS SAKE". my new emails hit 30,000 in a few minutes.
the entire NG email system was down for more than a day.
two days later i got called into my boss's office and he explained that top-tier management at NG had demanded that i be fired. my "oh no not again" was the last email most people saw before the system exploded. a very heated conversation between my supervisors and NG executives apparently just barely saved my job, but my supervisors were not pleased either and mentioned this would go on my permanent record (i thought that was just a high school thing). it didn't matter that i didn't actually do anything to cause the crash. i had merely made myself visible at the wrong time, and NG wanted someone's head.
so glad i don't work there now.