Those who take tiny, almost insignificant differences between brands and magnify them into market changing impacts: Canon is behind on metric A, therefore Canon is doomed.
Related – those who take one metric and generalize across the technology: Canon has less dynamic range at base ISO, therefore Canon sensors are terrible.
People who do something stupid or unethical, start a thread about it, expect everyone to say "poor, poor baby," and then get angry and belligerent when people disagree. Among my favorites: The guy who took his new 6D out on a speedboat in the pouring rain and then was shocked that it quit working; the guy who talked a wedding photographer into letting him tag along as a second shooter and then undermined the photographer by showing the bride his "better" pictures, the guy who took a picture of an iconic building and fountain on a private school campus, tried to sell prints on the internet and was shocked that the college told him it violated their licensing requirements. Related to this are the people who have bad experience with a vendor (Canon or others), write in to the forum to complain and then get upset when others who have had good experiences with the same vendor say so. Here's a hint: if you want sympathy, tell your Mom, not an internet forum.
The terms "Fanboy" or worse yet "Fanboi." For everyone's information, one you use either of these terms, you are conceding that you can't win the argument with logic, so you have to resort to name calling.
"Experts" who write long treatises of technical gobbledygook that are more about showing off their superior knowledge than actually enlightening anyone. (Note: these experts are frequently proven wrong when Canon accomplishes things they have said are impossible.)
Condescending posts that imply that the writer has higher standards than others on this forum and therefore they can't possible be satisfied with technology that 99% of users find just fine.
Art critics whose entire experience consists of buying an Ansel Adams calendar once a year. They take great pride in their ignorance and insist that established artists lack talent and vision.
Is that enough?
