recent article in The Korea Times says it all by posing the question, "Do Koreans enjoy Internet freedom." For several reasons, the answer appears to be "partly." For example, the most recent report by Freedom House, Freedom on the Net 2013 ranked the internet in South Korea as only "partly free," mainly because of the blocking of certain political or social content. The report noted that political tensions with North Korea are a significant motivation for online restrictions. It also reported that the Constitutional court in August of 2012 declared that section 44(5) of the Information and Communications Network Act which required users to verify their real names before posting comments on major domestic websites was unconstitutional. However, other laws mandating real-name registration in specific circumstances remained in place. Censorship of the internet in South Korea is carried out by the Korea Communications Standards Commission (KCSC), which was established in 208 to maintain ethical standards in broadcasting and internet communications. As reported by Freedom House, "A team of 20 to 30 monitoring officers flag possible offenses, including obscenity, defamation, and threats to national security."
In general, the findings of the latest Freedom House report on internet filtering in South Korea mirror those of The Open Net Initiative.
There is more in The Korea Times report, including the continued widespread requirement that Microsoft's Internet Explorer and Active-X be used for banking and financial transactions.