As an overly passionate, silly geek, when I like something, I don't just "like" it. I tend to get excited in a very specific way, going into full fan mode fairly quickly (see this drawing for a visual explanation).

Once I get rolling, I become a constant broadcaster, excitedly telling my friends about my newest obsession, while I wave my hands around in the air for emphasis.

This excitement is called "fangirling" (or fanboying, as the case may be), and it's fairly common behavior when it comes to the nerd world. In fact, it even extends beyond nerds: Stamp collectors, vintage record experts, and doll fanatics have their moments, too. We all light up when we get a chance to talk about the thing we love. When we share our enthusiasm, we welcome another person into our inner circle.

Sometimes, though, in the midst of marathoning yet another Asian drama with impossibly good-looking leading men, I'll catch myself wondering: Is my fandom escapism? And can it go too far?

All pleasures can lead to escapism, but where do they cross over into obsession? Are you obsessive if you spend each year crafting yet another insanely detailed Final Fantasy costume to wear to Dragon Con, or are you merely nurturing your creative pursuits? Is an encyclopedic knowledge of Star Trek history a good thing, or does the need to keep it up-to-date eventually edge out the necessities of life?

If there's one sect of fandom that's all about creating worlds to escape to, it's fan fiction. Magan Cubed, who has been actively involved in the fanfic community for over a decade, said fandom is usually a harmless social networking tool. But at its worst, it can become dangerous, leading to stalking or harassment, she said.

"This tends to happen when a camp of fans become overly entitled," Cubed said, "They begin to feel that they have a say in how the source material is written, presented, cast, etcetera, and that the creative staff is wrong for not following their wishes. This often presents itself as a sense of ownership over the actors of a film or television series, and has resulted in threats against the actor and his or her loved ones, both online and in person at conventions."

In a recent example, a contingent of fans of the show "Supernatural" began calling themselves "The Silent Majority" and started a campaign to write the upcoming season as they saw fit, claiming the show's writers had betrayed the core viewership.

"This group had also sent threatening and invasive messages to members of the cast and their wives, and attempted to get cast members fired from the show," Cubed said. "Ultimately this campaign went nowhere, but it was a scary reminder of how some fans can lose sight of reality."

This sense of entitlement is typical stuff on the internet, especially in the form of seemingly endless –and ultimately harmless - rants on fan forums.

America has seen it's share of fan-turned-obsessive, as is evidenced by celebrity stalking cases. Across the globe in South Korea, there's a completely different form of over-the-top fan behavior going on.

Korean pop stars have their own special brand of stalker, called "saesaeng (pronounced 'sah-sang')." These female groups go to extremes to enter the personal lives of the idols they adore, working closely together so they can achieve success. They are often seen hovering in the background of photos of pop idols, sometimes crammed up against the windows with their faces pressed to the glass in hopes of getting a glimpse of the stars.

They have been known to work around the clock to pursue celebrities in taxis, break into their homes, and buy and sell their personal information online, including identification numbers and telephone numbers, said Bianca Gomez, who runs Korean pop culture blog Angry K-Pop Fan.

K-pop stars JYJ have been one of many bands that have been targeted by saesang fans, but they are one of the few that reacted publicly to them, causing waves of discussion in the fervent fan communities.

Unlike paparazzi, saesang have one aim only: To get as close to the idols as possible, she said.

"The extreme behaviors and acts [saesangs] exhibit make it hard to believe that their motivations are just as simple as that of any other fan," she said. Healthy fans, she said, admire their favorite idol and are dedicated to supporting them all the way.

"In Korea, [saesangs] are walking paradoxes: they cause harm and distress though they don't mean to; they love the celebrity but seek complete possession of them; and they are deemed as outcasts by their peers," Gomez said.

Shunned by the bulk of their collective fandoms, saesangs socialize in self-managed, highly organized networks, she said.

"They are assigned responsibilities and fulfill them impressively, their information-finding skills are top-notch, and their ability to stay connected with each other and keep up with the fast-paced schedules of their idols is astounding," Gomez said.

This social organization sets saesangs apart from the solitary celebrity stalker we're used to hearing about in the US, Gomez explained.

So do Korean laws concerning privacy.

"We do not have much experience in protecting privacy," Lee Jin-ki, a law professor at Sungkyunkwan University, said. South Korea, he said, is in a transitional period, changing from a group-oriented to an individual-oriented community. As such, saesangs are not arrested for invasion of privacy. They can, however, be arrested for defamation, blackmail or threat.

"Anyone can get severe punishment for insulting someone both offline and online. It's not about whether or not we have the laws, but rather about people's mindsets," Lee said.

James Turnbull, lecturer and consultant on Korean issues, says the saesang phenomenon is just another necessary tool that the Korean advertising industry uses to keep all eyes on their idols. This may be another reason authorities tend to look the other way when it comes to saesang activity, Turnbull said.

"Obsessive saesang behavior is merely a logical, albeit extreme, side-effect. And it has had a long time to develop, too. Middle-aged women, with the financial resources to be saesangs, began dominating fanclubs in the mid-2000s. We're only going to see more of it so long as illegal downloading and the current glut of music groups forces management companies to rely on endorsements for profits," Turnbull said.

Mindy Mechanic, a clinical psychologist specializing in Post-Traumatic Stress Disorder and an associate professor of psychology at California University, said the behavior demonstrated by saesangs is profoundly culture-bound, and must always be understood in that context.

The group dynamic among these types of fans allows a sense of anonymity when the members violate the personal boundaries of celebrities, Mechanic said. In the case of saesang fans, it's easier to forget that what they are doing is disrespectful because they are surrounded by others who will join their cause.

But if they pursue a celebrity on their own, Mechanic said, it may mean facing consequences for their actions toward the person they romanticize.

“Many stalkers, even those stalking public figures and celebrities, are mentally ill and laboring under false beliefs. However, these group fans are likely more like groupies ... acting in concert with other adoring fans and attempting to get close to or connected to their greatness," she said.

Gomez agreed.

"There's a sense of importance and identity that is fostered by not only 'connecting' with a celebrity, but by finding other fans via their involvement in these networks," she said. "In the case of sasaeng fans, the pursuit of a fandom gives them something their own lives, and the people in them, are failing to provide."

In your mind, what's the difference between a hobby, a passion, and an interest that's gone too far? Is there any difference between being a devoted fan and being an obsessed fan?