I work for a global environmental engineering firm. This morning, one of the team leaders sent a mass email out to the entire division (~5000 people) asking for help solving a very specific problem with a broken lid on a test well.
He apparently got several positive responses because suddenly the whole division started receiving emails detailing the conversation. All the respondents were hitting "Reply All."
Of course, then people started politely requesting that their names be removed from the distribution list, but THEY were all using Reply All too. Soon everyone in the division had a string of emails flying back and forth that were only relevant to maybe five people.
Finally, I sent out an email saying that if we all stop replying to all, the emails would go away.
I then got something like 25 emails directly from people telling me I am awesome.
Best Monday Ever.