Strange things happen when an entire country is hooked on high-speed Internet.

Dear Abby has yet to receive a letter on this one. Last September Han Sang, a 14-year-old boy in Seoul, stole $35 from his parents to buy sunglasses and other accessories. The petty thievery was bad enough, but what really irked his dad, Kim Sung Bae, was that none of the stuff he bought was real. They were for the animated character, or avatar, the boy used as a stand-in for himself on the Internet. Han was spending four hours each night hanging out online with his friends and wanted his virtual stand-in to look as cool as possible.

Kim punished his son with an Internet curfew: No more surfing after midnight. Every Sunday afternoon would be Internet-free family time, and Han Sang would have to watch TV with his parents for a few hours a week. His parents, in return, promised to visit Han's virtual worlds with him.

South Korea has gone gaga over broadband. This nation of 46 million people, packed into an area smaller than Virginia, has quickly become the world's most wired nation. Politics, entertainment, sex, mass media, crime and commerce are being reshaped by a population as online as it is offline. Some 11 million homes, or 70% of the total, have broadband accounts, and at peak times just about all of those homes are online. Nearly two-thirds of Korean mobile phone users have shifted to so-called third-generation handsets that offer speeds up to ten times that of mobiles in the U.S. Here, residential broadband isn't expected to enter 50% of homes until late 2004.

Ubiquitous, fast and cheap access to the Internet has upended Korean society in dramatically unexpected ways. Depending on whom you ask, its experience should serve as either a warning or a triumph for the rest of a world racing to deliver broadband to the masses. Korean marriages are fraying as spouses cheat on each other through video chat. Psychiatrists are swamped with patients coming in for cures to online addiction. One man even died last year from a heart attack brought on by the stress of spending days waging war in an Internet game.

Koreans realized they had entered a new era after the last presidential elections. By 11 a.m. on Dec. 19, exit poll results showed that the iconoclastic Roh Moo Hyun, 56, a 2-to-1 favorite among youth, was losing the election. His supporters hit the chat rooms to drum up support. Within minutes more than 800,000 e-mails were sent to mobiles to urge supporters to go out and vote. Traditionally apathetic young voters surged to the polls and, by 2 p.m., Roh took the lead and went on to win the election. A man with little support from either the mainstream media or the nation's conglomerates sashayed into office on an Internet on-ramp. The traditional Confucian order had been flipped upside down, and a symbolic transfer of power from elders to youth took place.

Thousands of giant online fantasy worlds are populated by real people interacting virtually, often representing themselves with animated characters in a blend of game play and chat. One online fantasy game, Lineage, features 50 worlds, each so big it takes six hours just to walk from one end to the other. At times 320,000 or more people posing as spiders, beautiful women, mighty warriors or half-snake/half-humans communicate by voice, by typing, with hand signs and by fighting, running away and even embracing.

In the U.S. the tech sector looks to broadband to rescue it from a slump. Korea makes the prospect plausible. A Korean firm called NCSoft has already become the world's largest online gaming network, with 3.2 million subscribers paying $25 per month. It has the potential to beat both Microsoft's Xbox Live and Sony's broadband PlayStation networks in the race to dominate online gaming. Last year NCSoft bought ArenaNet, a U.S. gaming company founded by the creators of the hit multiplayer games Warcraft, Starcraft and Diablo. The Korean game networks already have a head start next door in China. A new Korean game called Fortress has 35 million players there.

Hanaro, the country's top seller of broadband access, and its nemesis, Korea Telecom, are racing to build the world's most advanced wireless Internet infrastructure. Hanaro may soon approve a $1.2 billion cash infusion from a group of investors led by U.S. insurer AIG. If the deal goes through, it would be Korea's largest foreign investment to date. The idea is to have base stations everywhere beaming Net connections at 2.4 megabits per second--faster than top cable modem speeds--so that people can be connected no matter if they are in the street, in a car or at a restaurant. People could use the same e-mail and network identity everywhere, on landlines or over the air.

Firms like Samsung and LG are inventing new types of handheld devices with voice-recognition and big screens to help people defend their virtual castles no matter where they are. At least 80 foreign companies have set up research sites in Korea to tap into this gigantic broadband laboratory. Even though Microsoft gets only $200 million in yearly revenue from Korea, it has just invested $500 million in Korea Telecom, in part to test plans for ubiquitous computing. Microsoft got a glimpse of this concept two years ago, when a small Korean Internet site began to show a movie clip of a famous actress having sex with her manager. The site was overwhelmed as, within three days, the entire country accessed it by various means.