A few months back, the Caltrans Performance Measurement System (PeMS) opened up a brand spanking new forum where people could discuss how they used the group's traffic data. They created an email list to tell everyone about the new forum. The problem is that PeMS used a single address to email everyone. So when someone "replied all," he would in turn email every single person on the list.
What followed was a long thread of emails that (entertaining) morning. This is that email thread. It got ugly quick (and kind of inappropriate towards the end). Let this be a lesson to you site administrators.