I don’t remember where I heard about this originally, as I heard about it about a week ago, but this entry from E-Media Tidbits sums things up nicely:
Online revenge is sweet when cooked up by a faux Scandinavian puppet chef. A digital stew began two weeks ago when the Norwegian manufacturer of Web-browsing software Opera claimed that Microsoft was intentionally feeding Opera users a faulty HTML style sheet whenever they visited the MSN website, causing content to disappear and users to think that something was wrong with their Opera browsers. Opera enlisted the Muppet Show‘s incomprehensible Swedish Chef for revenge and released the “Børk edition” of the Opera browser, which turns the contents of MSN into mock-Scandinavian gibberish. The Internet Advertising Report details the delicious ruckus.