MOKCHEON, South Korea — The compound — part boot camp, part rehab center — resembles programs around the world for troubled youths. Drill instructors drive young men through military-style obstacle courses, counselors lead group sessions, and there are even therapeutic workshops on pottery and drumming.

But these young people are not battling alcohol or drugs. Rather, they have severe cases of what many in this country believe is a new and potentially deadly addiction: cyberspace.

South Korea boasts of being the most wired nation on earth. In fact, perhaps no other country has so fully embraced the Internet. Ninety percent of homes connect to cheap, high-speed broadband, online gaming is a professional sport, and social life for the young revolves around the “PC bang,” dim Internet parlors that sit on practically every street corner.