I've seen a big international bank internal network shut down because someone added a group mail of +- 10 000 people to a thread with jokes.
Significant percent of these people were on holidays at the time so they responded automatically to each other with "out of office" messages and finally the network couldn't handle it.
> I've seen a big international bank internal network shut down because someone added a group mail of +- 10 000 people to a thread with jokes.
Those stories are always entertaining. But honestly, those organisations only have themselves to blame.
Filtering and stopping these internal chains shouldn't be any harder than basic spam filtering. Mostly easier, because your filter inputs are not as adversarial.
Significant percent of these people were on holidays at the time so they responded automatically to each other with "out of office" messages and finally the network couldn't handle it.
Emails are serious business ;)