According to Pan Chien-chih, a psychiatrist at Taipei's Wanfang Hospital and well known to netizens as the blogger "BillyPan," Internet vigilantes are an online demonstration of the concept of "strength in numbers." By marshaling the power of crowds, they are able to collect large amounts of information on any given event or person, and then compare and contrast that information to piece together the truth. Often just one photograph, one video, or just the slightest tangential piece of information can prove to be a lead for these detectives, helping them uncover the circumstances of an event or information on the people involved. At times, their speed can be such that even professional law enforcement can be left astonished.

And with online communities and social networks on the rise, individual netizens can simultaneously have blogs, online photo albums, microblogs, Face-book profiles, MSN profiles, and more, all, for the sake of convenience, done under one identity. Through the comparison and contrast of information from these accounts, people's backgrounds can easily be dug up and made public.

Even if you haven't left any tracks on the Internet yourself, with personal information spread so widely in the Information Age, if you've ever been involved with a company, a school, or a community, or signed up for an exam, participated in a competition, or even won a lottery, these disparate threads can end up revealing your identity to all involuntarily or even unwittingly.

Simply typing in a couple of keywords into Google is a rookie move for these wannabe detectives, as Pan explains: the Internet is home to all kinds of different databases, and some of them, whether due to file format or due to being behind a paywall, cannot be accessed by Google, but serious Internet detectives can still get into them.

Additionally, interpersonal relationships in the digital world can be a source of information. Pan himself has over 6,000 followers on his Plurk page, and he has put this crowd through various experiments, such as arriving at restaurants for dinner, and before his meal has arrived taking a photo of the empty table and posting it to Plurk to see if people can guess where he is. Before even 10 minutes have passed, someone will always have cracked the mystery. Clearly the human brain still has the edge over computers; "Everyone online is like a piece of the cloud," says Pan, in reference to the concept of "cloud computing."

And thus through online connections and the "six degrees of separation" concept (built on the results of the 1967 "Small World Experiment" conducted by Harvard psychology professor Stanley Milgram), human-driven, social-engineering-type search methods can be highly accurate, even surpassing the speed and accuracy of computerized searches.

As Facebook has grown in popularity, so have concerns over privacy, becoming a major topic of debate.

The Chinese term for these Internet detectives ("renrou souxun" or "human flesh search engines") was coined in 2001 on MOP, one of China's top two online forums. The term was the name of a dedicated subforum, originally intended to provide a place for users to ask each other questions and find more accurate answers more quickly through the power of the crowd. At first, it was mostly just about trivial things like entertainment gossip, such as controversies over whether or not female celebrities had had plastic surgery or finding photos of celebrities as children. However, the discovery of the so-called "Kitten Killer of Hangzhou" in 2006 led to a redefinition of the use and function of these "human flesh search engines."

This incident was sparked off by screenshots from several videos that soon spread across the Chinese 'net. In them, a middle-aged woman dressed in black and wearing a pair of stilettos cruelly crushed the head of a small kitten with her feet, killing it, all while continuing to wear a nonchalant smile on her face. This astonishing show of cruelty aroused the ire of netizens, and many of the most infuriated soon set their sights on her, swearing to uncover her identity.

By tracing her domain registration and online identity, as well as determining the location where the videos were shot by digging through photographs, in just six days the woman, the cameraman, and the person responsible for uploading the video all had their real-life identities revealed. Despite originally thinking their tracks were hidden, these three lost their jobs and were subjected to official investigation, as well as being forced by social pressure to make a public apology. In the end, they were driven from their small village in Heilongjiang and seemingly vanished into thin air. Chinese netizens hailed this as a victory for "Internet justice."

Since then, people as highly placed as corrupt officials committing crimes and demanding bribes, to those as low as cheating husbands or ordinary people in self-shot pornographic photos have been revealed; all it takes is the arousal of the curiosity or anger of the masses on the Internet for these "search engines" to get into gear.

International media such as the BBC, New York Times, and Los Angeles Times have all reported on this Chinese Internet phenomenon, with the latter even saying, "The private eyes in China's most famous detective agency rarely sleep, are relentless in pursuing their prey and can put Interpol and Homeland Security to shame. Oh, and they work for free."

(from left to right) Taiwan's PTT and Mobile 01, along with MOP and Tianya in China, have each become homes to some of the regions' most feared Internet vigilantes.

Generally speaking, what gets Internet detectives going is either unlawful behavior or behavior that, while not unlawful, goes against mainstream moral values. In terms of those that have hit the Taiwanese media spotlight, there are several broad categories: national public interest issues (such as the Diane Lee dual-citizenship scandal), self-indulgent and inappropriate acts (such as vandalism and people prank-calling fundraising call-ins after Typhoon Morakot), unethical relationships (such as legislator Wu Yu-sheng's affair with Rebecca Sun), and incidents of animal abuse. Others, such as threats of suicide, also rally the online masses, transforming the online collective into vigilantes or guardian angels.

Another example is that of a case of animal abuse in 2006, wherein a Mr. Fang "trolled" a cat-lovers message board with photos of kittens in boiling water, with their legs bound. These Internet detectives not only brought their full force to bear on the "case," they even took it into the offline world, going from house to house in a blanket search of the Neihu area of Taipei comparing the bars on apartment windows to those seen in the pictures, and ultimately finding evidence that proved critical in nailing the culprit.

In the wake of this incident, animal protection groups organized protests calling for comprehensive reform of the Animal Protection Act, prompting the Council of Agriculture to put forward amendments to the APA that em-power the COA not only to levy administrative fines on offenders, but also to press criminal charges, with the possibility of jail time. This is one positive outcome of such Internet vigilantism.

But just as water can lift boats, it can also sink them, and Internet vigilantism can be a double-edged sword; while such actions have shown the tremendous power of the Internet, they have also brought with them controversy and questions.

People are, after all, prone to being blinded to reason by emotion, and on the Internet there is no demand that one maintain objectivity and decorum as one must in real life. With no system of checks and balances, Internet vigilantism can often degenerate into people venting their personal anger, and even lead to legal proceedings after the event. Sometimes, rather than a tool for righting perceived injustices, it can actually become a tool of personal torture, turning from just vigilantism to violence.

In the aforementioned case of Mr. Fang, his age, occupation, address, and other personal information were posted online, and cat-lovers from around Taiwan began waving banners and holding all-night candlelight vigils outside his home and his parents' home in protest. Some consider these actions to have disrupted the community and hurt innocent friends and relatives. Some from the Internet even essentially besieged the man to "show him what for," spreading the word so he would be forever unemployable, and other such actions. Whether or not such emotional behavior is taking things too far has become a topic of much debate.

(from left to right) Taiwan's PTT and Mobile 01, along with MOP and Tianya in China, have each become homes to some of the regions' most feared Internet vigilantes.

Another such incident began on the popular message board PTT. PTT has over 1.5 million registered users, with as many as 150,000 people online at peak times, and with such numbers, a simple interface, and a huge amount of data online, any given topic can explode with astonishing speed. As a result, PTT has effectively become the "base camp" for Taiwan's Internet vigilantes.

In October 2009, on a PTT discussion board about sexual issues, one female user wrote about her sexual experience, but was uncomfortable with posting it under her personal account, posting instead to an online mailbox from which the board's moderator would then collect and publish the posts.

A graduate student from National Taiwan University, unfamiliar with the system, mistook the public account for the woman's personal account, sending to her a private invitation for a one-night stand, and ended up being the target of mockery and ridicule when the moderator made the letter public. This caused a tremendous stir, and the man concerned quickly got online and posted an explanation and apology.

But some users refused to let it go and continued to agitate for vigilante action, not only digging up his personal information, but even targeting the man's girlfriend. This drove Mr. Zhou, the man involved, who had previously claimed his account had been hijacked, to once again get online and profusely apologize and come clean.

The next day, the story hit the mass media, and continued to generate discussion. Some online, wanting to keep the show rolling, said that his trying to "get a bit on the side" and having claimed his account had been hijacked meant he deserved what he was getting, and continued to post updates. Another, more sympathetic group of users felt that although he had been in the wrong, the actions of those other users were over the top and unfair.

"DearJohn," a blogger and long-term observer of online communities, has asked what crime the aforementioned Mr. Zhou has committed that some online can't seem to let go of him? A man privately inviting someone for a one-night stand is nothing new, and all he is really guilty of is a momentary indiscretion and sending an email to the wrong address. But this one slip seems to have ignited a fuse that has blown up in his face, doing damage that will be difficult, if not impossible, to repair."Nothing is secret on the Internet, and people will always be able to dig up this man's past and use it against his future," notes DearJohn.

Similarly, veteran"villager" (a term used on PTT to refer to users drawn to more active topics, adopted from the Stephen Chow movie Hail to the Judge), 13-year message-board veteran and animation director Lin Shih-yong has taken his observations and reflections on online culture to create a 3D animated film entitled Woodman Movie Edition: War of BBS World.

Says Lin, throughout much of his membership of PTT, he was just a lurker, silently watching the excitement, but as more and more incidents blew up from the board, whether the activities of Internet vigilantes, the media lifting stories from the boards, the tyranny of the majority, or whatever else, the growing amount of"cyberbullying"got him thinking: what really constitutes"online justice"?

Woodman Movie Edition: War of BBS World, Taiwan's first message-board-themed film, takes its inspiration from real-life events. It also includes a number of in-jokes and jargon familiar only to avid message-board users, earning it much acclaim from that particular demographic.

In 2008, in the Chinese province of Si-chuan, another tragic tale was woven at the keyboards of the Internet vigilantes. A man, wanting to find a girl he had acrimoniously broken up with a few years earlier, falsely claimed to have been diagnosed with leukemia, to not have much time left, and to have been cruelly dumped by his girlfriend, expressing his hope that the Internet could help him"get justice."

Netizens, believing his story to be true, soon dug up his ex-girlfriend's phone number and address, as well as flinging insults at her. Her information in hand, the man went to her home to hash out the situation, but when things turned bad for him, he stabbed the 20-year-old-as he had been planning to all along-ending her short life. Although after the event, netizens involved felt responsible and regretted having gone along with his story blindly, thus effectively becoming accomplices, all the regret in the world cannot turn back time.

Liao Yiling, a mental health counselor who has counseled many such members of the "N generation," says that online, the real and the fake are intermingled, and it can be difficult to distinguish truth from fiction. Although most cases of Internet vigilantism spring from a desire to do good and uphold moral values, this can mean that users who get involved in such activities will readily believe that they are "doing the right thing," even though that may just be illusory, and with so many members of online communities having an "all for one" sense of belonging, along with follow-up media reports, many people online are even more eager to get on board with "upholding justice" as they see it.

Woodman Movie Edition: War of BBS World, Taiwan's first message-board-themed film, takes its inspiration from real-life events. It also includes a number of in-jokes and jargon familiar only to avid message-board users, earning it much acclaim from that particular demographic.

From the legal perspective, lawyer and "villager" Lin Bonan says, offences under the Personal Data Protection Act and libel, slander, and other defamatory behavior covered by Articles 309 and 310 of the Penal Code are two of the most likely forms of illegal behavior to be engaged in by Internet vigilantes.

Lin explains that the Personal Data Protection Act, passed in April 2010 and due to come into force in the first half of 2011 to replace the existing Computer-Processed Personal Data Protection Act, is intended to address the currently chaotic flow of personal information being transmitted online.

The existing act only applies to eight sensitive industries, including credit, finance, and mass media, but the new act is broader in scope, applying to individuals regardless of occupation, if they violate the privacy of others. Similarly, the scope of protection is being broadened, extending to cover the personal information of public figures.

As applied to the example of Internet vigilantes, if anyone online, in an instance with no relevance to the public interest, posts personal information or makes slanderous comments, they can be found in breach of the law. However if a user is only reposting or reformatting publicly and legally available information, such behavior will not be considered illegal. Anyone who has their personal information revealed online also has the right to request such posts be deleted by the website hosting them.

In spite of this, Lin notes, in all actuality information spreads rapidly across the Internet, and as you can imagine, the parties involved have no realistic way of getting every single post deleted, and even trying to do so could just make the information more in demand.

Additionally, when it is in the public interest, the police are able to use the techniques used by Internet vigilantes to obtain evidence, potentially making netizens involved "virtual deputies." Will this make netizens more eager than ever to indulge their dreams of becoming a 21st-century Sherlock Holmes, or will it scare them off for fear of accidentally targeting innocent people? This remains to be seen.

(from left to right) Taiwan's PTT and Mobile 01, along with MOP and Tianya in China, have each become homes to some of the regions' most feared Internet vigilantes.

Weber Lai, chair of National Taiwan University of Art's Department of Radio and Television, says that Internet vigilantism itself is simply a tool, and what matters is how it is used. However, in this new-media age, the distinction between public and private is becoming increasingly blurred, and as former US FCC chair Mark Fowler has noted, the concept of the "public interest" is broad-anything that arouses the interest of the public is by definition in the public interest.

Weber Lai notes that it is increasingly less avoidable in the Internet age that your information could be traced, and all netizens can do is try and take precautions in advance and be more vigilant in protecting their personal information. At the same time, if they choose to divulge information online, they must be prepared for the fact that anyone could be the next target of Internet vigilantes.

Blogger DearJohn has a different perspective: if personal information is so hard to protect online, he says, why not just take the path of least resistance and, as is popular in South Korea, simply use your real name and be totally transparent?

South Korea, where Internet penetration is high and over 75% of the population are online, has also faced the problem of Internet vigilantes in recent years, along with all that such behavior brings with it.

Several incidents of vigilantism and online rumor-mongering have been big news, including not only driving parties to mental illness, but even leading to the suicides of popstar Unee and actress Choi Jin-sil. This series of tragedies became the source of much discussion and reflection in South Korean society, and a consensus developed to put in place a "real name" registration system which was considered the best way to reduce the incidence of cyberbullying.

Such a system was originally proposed by the South Korean authorities in 2002, but due to concerns over netizens' right to privacy and freedom of speech, it was not until 2008 that it was implemented, first having to pass through the legislative and legal systems. Currently 35 of South Korea's biggest websites have implemented the system.

DearJohn says that thus far under that system netizens can still use pseudonyms to maintain superficial anonymity, but deep down they all have their concerns and realize they can no longer stay hidden in the shadows throwing stones anymore. At first glance, this approach seems to want to take things back to the pre-Internet days, "but who says the online and offline worlds have to be separate? Who says they must always be two parallel worlds?" asks DearJohn.

The two sides of the Internet vigilantism coin demonstrate that while humanity has a sense of justice and solidarity, it also has a violent, out-of-control, ugly side. In the end, which of these two faces will the phenomenon of Internet vigilantism ultimately lean toward?

(from left to right) Taiwan's PTT and Mobile 01, along with MOP and Tianya in China, have each become homes to some of the regions' most feared Internet vigilantes.

Woodman Movie Edition: War of BBS World, Taiwan's first message-board-themed film, takes its inspiration from real-life events. It also includes a number of in-jokes and jargon familiar only to avid message-board users, earning it much acclaim from that particular demographic.

Woodman Movie Edition: War of BBS World, Taiwan's first message-board-themed film, takes its inspiration from real-life events. It also includes a number of in-jokes and jargon familiar only to avid message-board users, earning it much acclaim from that particular demographic.

(from left to right) Taiwan's PTT and Mobile 01, along with MOP and Tianya in China, have each become homes to some of the regions' most feared Internet vigilantes.

Woodman Movie Edition: War of BBS World, Taiwan's first message-board-themed film, takes its inspiration from real-life events. It also includes a number of in-jokes and jargon familiar only to avid message-board users, earning it much acclaim from that particular demographic.