Brad Templeton has mined the Google Usenet archive to trace the etymology of the term "Spam" in reference to unsolicited commercial messages.
The first major spam came on January 18 of 1994. Every single newsgroup found it it a religious screed declaring: Global Alert for All: Jesus is Coming Soon.
This one caused a ton of debate and controversy. The student who sent it off got roundly punished.
Normally in USENET you can post a message to more than one newsgroup using the "crossposting" mechanism. The advantage with this is that the message only goes out once, and people who read both newsgroups only see it once. This feature is highly useful if not abused, yet most major conferencing systems never implemented it.
However, it was not practical to crosspost to every single newsgroup, nor desired. Still, this event provided a button at the USENIX Unix conference saying "Jesus is coming and he doesn't know how to crosspost."
