There's no easier way to instantly piss off nerds than by messing up the name of a popular character, like calling the wizard in Lord of the Rings "Crandolf" instead of "Gandolf," or saying "Bubba Feht" instead of "Bobba Feht."
If there's one things nerds cannot resist, it's gleefully correcting your spelling mistakes, so you better double-check the next time you accidentally write "FUMBLEDOOR" instead of Dumbeldoor! Haha - nice work there, Einstien!
Another sure-fire way to anger commenters is by misusing a word or expression, i.e. "literally" or "ironic". People LOVE to correct your vocabulary mistakes; even if you barely mess up a word, commenters will act like it's the most tortuous thing that's ever happened, and they're just TOTALLY decimated by your attention to detail. Whaaatever.
Penultimately, making these mistakes will get you literally crucified, with very few acceptions. Which is, dubiously, exactly what happened to Jesus. Now THAT'S ironic.