The nation’s largest online forum, 2channel, draws millions of people ranging from the benign to the malignant, from police hunting criminals to politicians and corporations keeping their ears to the rail of public opinion.

Key to 2channel’s power, and gravitational pull, is its anonymity. Its users can be frank, slanderous, even criminal.

Police use 2channel to combat crimes, especially posted threats. When they come upon such malevolence, they solicit IP addresses and other information on the parties involved.

Following are questions and answers regarding 2channel:

What is 2channel?

It is an open-to-anyone text-only online bulletin board — Japan’s largest and arguably one of biggest worldwide.

Because of loose rules, messages can be posted anonymously.

Hiroyuki Nishimura created 2channel when he was a college student in Arkansas in May 1999. Hiroyuki, as he prefers to be known, is now a board member of Niwango Inc., which operates the video-sharing Web site Nico Nico Douga.

His brainchild is now divided into about 50 categories, among them recipes, real-time coverage of news events, sex gossip, high-tech gadgets and computer news.

Each category has dozens of topics, and those in turn have hundreds of threads, each with up to 1,000 postings.

How widely accessed is 2channel?

Nishimura wrote in his book “Bokuga 2channel wo Suteta Riyuu” (“The Reason I Abandoned 2channel”), published last June, that the Web site has 10 million users per month.

Junichiro Nakagawa, who authored “Webu wa Baka to Himajin no Mono” (“Internet is Meant for Idiots and Bored People”), published last April, said 2channel users number between 12 million and 16 million.

Why has it become so popular?

The huge success has been attributed to users being able to post and exchange messages without having to reveal their identity.

“It’s where idiots can be the idiots they want to be. It’s where they are allowed to say things they don’t need to take responsibility for,” Nakagawa said, adding that “in the world of the Internet, winner takes all. It’s more fun to go to a bulletin board where more people write comments.”

What are 2channel’s sources of revenue?

The bulletin board carries a number of banner ads, mostly from companies peddling consumer loans and adult content products. Also, people are required to pay to read past postings, which are stored in separate archives.

Nakagawa said the majority of revenue probably comes from the ads, because that is typically the business model of similar Web sites.

Who owns 2channel now?

Singapore-based Packet Monster Inc., to the surprise to the Internet industry, bought the operating rights from Nishimura in January 2009 for an undisclosed sum.

Little is known about Packet Monster Inc. In his book, Nishimura said it is more interesting to leave a veil of mystery over the firm’s workings.

It has been speculated that Nishimura sold off the operating rights to avoid lawsuits involving 2channel — an allegation he neither admitted nor denied in his book.

“It’s amusing” to let the speculation stand, he wrote.

“There were few things I was supposed to do in operating 2channel. That was one of the biggest reasons” why the operating rights were sold, he also wrote.

Has there been any significant change for users after 2channel was sold?

Just as Nishimura predicted, nothing changed. He said in the book that he had little to do with day-to-day operations because procedures, including deleting problematic postings to keep the operation smooth, had already been systemized and there was no room for him to intervene, except that he sometimes had to mediate disputes among volunteers who managed the site.

What major controversies have involved 2channel?

The forum often draws flak for spewing slander and carrying information harmful to the public.

For example, someone posted information on how to produce hydrogen sulfide, a lethal chemical used for painless suicides.

There have also been many criminal cases involving 2channel users.

A man was charged last October for posting a death threat targeting land minister Seiji Maehara.

A yakuza indicted for ramming a truck into a car carrying a rival mob boss last September has allegedly admitted he committed the act after reading a 2channel posting that claimed he was scared of the rival organization, according to a report by the Asahi Shimbun.

There are also many potential cases of defamation and privacy infringement in 2channel postings.

Nishimura has been targeted by several lawsuits seeking deletions of libelous postings and compensation for damages.

He lost most of the suits because he did not show up in court. But he also has never paid any of the court-ordered compensation to plaintiffs, according to media reports. However, there were media reports Monday that compensation was paid in one case through the publisher of one of Nishimura’s books.

The writer Nakagawa meanwhile said 2channel can be addictive. He said research using software to detect the source of 2channel postings revealed that one party wrote about 1,500 entries in a single day.

Does the site convey any good or useful information?

If users can manage to separate fact from fiction, 2channel can possibly serve as an excellent source of information.

For example, industry insiders have posted revealing information. Such postings are sometimes condensed into popular books.

Hundreds of volunteers post flash news — most of which is copied and pasted from other news Web sites — 24 hours a day, and participants exchange comments.

Also, 2channel sometimes helps police and courts. It holds IP addresses and other related information that can identify people creating threads, or topics, and posting responses to the threads.

In some past cases, 2channel’s operators provided such information when police requested help in catching criminals.

What is the most recent news?

This would be the March 1 attack on 2channel sourced to South Korea.

Servers of 2channel located in San Francisco were overwhelmed with hits from more than 20,000 people in South Korea. The attack subsequently shut down more than half the 2channel servers that day, the weekly magazine AERA reported.

The attacks were reportedly organized in retaliation for many 2channel postings that disparaged South Korea, including insults leveled at Olympic figure skater Kim Yu Na while heaping praise on her Japanese rival, Mao Asada.

There apparently are many rightwing users who post derogatory references on 2channel against South Koreans.

The Weekly FYI appears Tuesdays (Wednesday in some areas). Readers are encouraged to send ideas, questions and opinions to National News Desk