Arlen Theory is a maxim first posited on Davis Wiki. The idea is that if a page doesn't exist, there is one surefire way to get fans of the topic to edit your wiki: Make a tiny, pithy entry talking smack about the the subject. Often as not, someone will come to "fix" the "vicious attacks", and the wiki will gain a new entry.
Use of Arlen Theory is not cool when you actually know something about the topic, but are too lazy to make the entry. Just edit the page already.
Related to Arlen Theory is "Cunningham's Law": The best way to get the right answer on the Internet is not to ask a question, it's to post the wrong answer.