A USENET newsgroup about one of the most popular characters from The Muppet Show, The Swedish Chef. Newsgroups in the alt hierarchy were totally unregulated, so anyone could create any newsgroup they so desired.
The bork.bork.bork part was added on as a joke. It comes from the little tune the Chef sings at the beginning of each sketch. The lyrics are completely unintelligible, except for the "Bork"s.
alt.swedish.chef.bork.bork.bork inspired a legion of imitators, who used the pattern for both good (alt.plastic.utensils.spork.spork.spork, alt.icelandic.waif.bjork.bjork.bjork, alt.french.captain.borg.borg.borg) and evil (alt.<real person's> name.die.die.die, alt.music.enya.puke.puke.puke). The question of newsgroups such as alt.wesley.crusher.die.die.die and
alt.barney.dinosaur.die.die.die being good or evil is left as an exercise for the reader. Many newsgroups were created with this format, so eventually someone created alt.adjective.noun.verb.verb.verb where all communication had to be done in alt.adjective.noun.verb.verb.verb format1.
Insults applied this way were undeletable, but they were also unfixable, as the person who created the famous
alt.music.enya.puke.puke.pukeSender found out.
1 mkb supplied me with this tidbit. Thanks.