SEOUL — The Korean TV market has long been a tough nut to crack for foreign programming, in part due to regulations and viewers’ support of local product.However, a newfound burst of popularity for American — and, to a certain extent, Japanese — series has propelled a sea change in public perception. Articles in the press on the popularity of “CSI,” “Prison Break” and other foreign programs are now a daily occurrence. One local magazine terms it nothing less than a revolution. “In the case of U.S. and Japanese TV series, such programs have first become popular through illegal downloading platforms, and now the price paid for legal imports is rising,” says Shin Eun-hyang of the Ministry of Culture and Tourism’s copyright division. Indeed, illegal downloading remains a huge hurdle for both imported and local TV series, despite government efforts to stop it. (Current laws call for a five-year prison term and $53,000 fine for anyone circulating illegal files). Although local dramas still top overall ratings, the rage for imported series is particularly strong among viewers in their 20s and 30s, with Internet communities playing a large role in spreading word of mouth. This has helped quicken an overall shift from the terrestrial channels — which devote only a few slots to imported dramas — to the growing cable sector. If current negotiations between the U.S. and South Korea result in further opening of the local TV sector, American dramas look poised to benefit.