Ever experienced a reply-all email bomb at work? That's when someone writes an email to EVERYONE, somehow addressing it to dozens of individual addresses instead of "Operations" or "All Staff"… and then everyone starts replying -- to all -- "stop replying to this thread!" ad nauseam.
In many private email setups, this sort of thing is prevented because only certain people are allowed to write to a special large group like "Operations" or "All Staff". The magic happens when the original sender accidentally uses the command to "expand -- replace this group name with the names of all of its members" on the To field.
Well, it happened at Microsoft this week. Reportedly 52,000 people are getting angry or laughing at a reply-all bomb thread, while sysadmins fight to clean up the mess.