Being told a truth you don't wanna hear isn't bullying. I'm not saying that's what you meant, here. I just want to point it out.
Like TF said, some people are very assertive and direct. Maybe they'll burst your bubble, but they don't do it in order to intimidate you, or to put you down.
I know it's a thin line to walk. If I'm to buy a weird-magic-time-travel necklace on Ebay, I'd rather have Harte tell me it's bogus. Then again, I love discussing the HDR and other time travel devices... So Harte probably doesn't agree with me there. See where I'm going with this?
I won't be surprised to see Harte tell a new member asking stuff about the HDR, or about a magic necklace, that he thinks it's a fraud. That's an opinion, that's fine by me if you're respectful. Now, is he allowed to harrass that member and remind him of his opinion everytime this new member replies or asks his / her next question? No, simply because it would prevent the discussion to take place. And that would be rude.
In other words, you're free to express yourself, as long as it doesn't prevent the discussion from taking place. Don't crash the discussion!
Does that make sense? Feel free to share how you feel and correct me. I don't pretend to know it all.
And thank you Harte for probably allowing me to take you as an example here.