Reading On the 20th Anniversary, an Oral History of the Web’s First Banner Ads, I came across this:
In April of 1994, two lawyers from Arizona caused controversy by spamming 5,000 Usenet newsgroups with a message offering their services helping resident aliens get Green Cards.
I remember how annoying it was that most of the newsgroups I read were spammed by that message. (That was before the thousand daily spam years, which were before Baysian spam filtering.)
I was actually waiting for my Green Card at the time.