While both Silverstein and Sierra are higher-profile bloggers than many of us, it's clear that anyone who enters the blogosphere needs to be aware of the types of people who get satisfaction out of online harassment. According to Derek Wood, vice president of clinical operations at PsychTracker Inc., a journaling site for people with mental illness, the harassment comes in two general forms: trolls and cyberstalkers. It's important for blog participants to understand the psychological makeup of both types so that if they encounter any type of online abuse, they'll have some idea of what they're facing and how to respond to it.

TrollsEssentially, a troll is a person who posts with the intent to insult and provoke others, Wood explains. The goal is to disrupt the normal traffic of a discussion group beyond repair. "A group is considered to be cohesively destroyed when two-thirds to three-quarters of the messages are a result of [trolls'] comments," Wood explains. They often target new users, who are more likely to take offense, hence the term "troll" (as in "trolling" for newbies).

Many trolls are characterized by having an excess of free time and are probably lonely and seeking attention, Wood says. "They often see their own self-worth in relation to how much reaction they can provoke," he says.Woods categorizes trolls in the following ways:

• Spamming troll: Posts to many newsgroups with the same verbatim post.
• Kooks: A regular member of a forum who habitually drops comments that have no basis on the topic or even in reality.
• Flamer: Does not contribute to the group except by making inflammatory comments.
• Hit-and-runner: Stops in, make one or two posts and move on.
• Psycho trolls: Has a psychological need to feel good by making others feel bad.

The last type, according to another victim of online harassment, who asked to be identified only as Tim to avoid further online trouble, are "sick individuals." At one point, he says, an online hobby community that he led was attacked by such a person. "We learned over time that he wasn't just some schmo having fun -- he seemed to have some formidable computer hacking skills as well as debating skills," he says. Even when site administrators tried to ban him from the system, he found work-arounds, Tim says. "He eventually went away, but he's still out there [on other discussion groups], doing his sick, twisted thing," he says.

Later, Tim was hit at a more personal level when another group of people set up a blog aimed at mocking and attacking prominent members of the hobby community, including himself. Some of the material included photographs depicting their targets being violated, he says. One individual was able to force the bloggers to remove the images, using the Digital Millennium Copyright Act (DMCA), the same law that helped Silverstein force the removal of the offensive images from the blog harassing him. Despite that victory, however, the bloggers continue, "and they used the DMCA notices as a way to further malign [the victim] in public," Tim says.