How far is too far, when you're being anti Twilight or Harry Potter?

I don't like when people go "Harry Potter/Twilight sucks" and they've never read the books or seen the movies. It's judging the stories before experiencing them. I also dont like when people bash certain characters when they don't even know their background.

I think when things get personal, things have gone too far :)

For me, too far is when you threaten, harm (physically, mentally, or emotionally), or insult someone.

I don't really have a "farthest" I would go. I'll debate against Twilight on this spot when I feel it necessary, I'll say I don't like it. But that's about it.

Since I'm a fan of both Harry Potter and Twilight, I'll have to use a different example for how far I would go to show how much I don't like something.

Nickelback, for example. I can't stand them. Now, I would post things like "I don't them" or "I think this band sucks," but I would never attack someone for liking them, which is something that a lot of people do here. Just because someone is or isn't a fan of something doesn't make him/her more or less intellectual than anyone else. It just means that they like something different. It does bug me when I see how people are fanning over Nickelback when I don't see the appeal at all, but that just means that I have a different opinion than them, and not that I or the fans am/are more intelligent than the other.

Something else that people do to show their hate, that makes absolutely so sense to me, is spending what seems like most of their time spreading their hate. They make websites, blogs, videos, and pictures solely dedicated to that thing that they hate and why they hate it. I don't understand why people want to spend their time thinking about why they hate something. Sure, I think about how much I don't like Nickelback when someone mentions something like "What do you hate?" But I would never spend most of my time writing about how much I hate them, or going to where there are fans and putting them down. I would much rather spend my time thinking about things that I do like and listening to bands that I like rather than something that I dislike.

tl;dr The farthest I would go to show how much I hate something would be to simply say "I don't like [insert thing]."

When one starts personally attacking fans of the other side.

Pretty far.

I think almost any physical manifestation is too far.
Burning a book or pictures of characters, buying a poster so you can throw darts, slapping people who are fans (or anything having to do with fans in general), attempting to stalk and threaten the actors.

Really anything that requires physical action.

the furthest I would go is to just say I don't like it.
I may write something down or doodle a little picture showing something funny a fan wouldn't appreciate (nothing violent or insulting), but I wouldn't ever distribute it to fans just to upset or annoy them. It'svery rare I do anything like that, though. My dislike for something is usually private.

I'll have a friendly debate with a Twilight fan, a discussion really, just explaining why I dont like Twilight and why I think HP is better, but to far is when you openly bash the opinion of another human being, and insult them over fictional stories.

when you attack a twiligher screaming "abra cadabra!" or "i hope voldy uses you as target practice you twi-diot!" [for h.p fans]

when you jump on a harry-humper screaming "i hope you sit on your wand nd it goes up your [bottom part]!" or "why dont you bite me wizdo!"

when you paint every dark spell/curse you know on a twi-s home/car.
when you put dementors on their lawn with a sign saying "if you dont let a vamp suck the life outta you these will!"[twi-s to wiz-s"

that or killing

-Burning the books.

-Lashing out on either fanbase about their intelligence, looks, or just being hateful in general.

-Saying things like "that author should have never been born", or any death threats.

-Insulting either fanbase if you have no knowledge about it.

-Hating it for the sake of hating it, and/or hating it because it's popular.

-Acting out physically towards the fans of either fanbase.

I don't think I'd go very far on hating Twilight. Debating, expressing opinions, and making polls is about all I do. I have friends who like Twilight, they ask why I don't, and I give them my opinion and that's about it.

I'd say when you've entered the physical realm of insults.

The farthest I would go would be like uploading pictures or something. I'm not that against Twilight like I used to be.

Basically, anything rude or offensive.

It's one thing to state you opinion, ex. "Harry Potter/Twilight sucks", but it's a whole nothing thing to just over-the-top bash the one you don't like.

Other unacceptable things would be like what others have said-burning books/characters posters, etc. Persecuting people for liking a certain series, threats, etc.

Basically, anything beyond politely stating your opinion and then explaining why is just not cool. I mean, why waste your time hating something?
Insulting or bashing what you don't like is just immature, and anything beyond that is just creepy/obsessive.

the possibilities are endless...