South Korea and "cyberviolence"

CNN has posted this report on cyberviolence in South Korea. The report is interesting for these aspects:

• South Korea is the world's most wired country, boasting the highest per capita rate of broadband Internet connections.
• The term cyberviolence encompasses anything from online insults to sexual harassment and cyberstalking.
• Prosecutors are beginning to respond to the threat posed by cyberviolence.
• Also responding is the government, who plans to introduce a bill that real-name authentication.
• Websites too are responding by actively seeking to filter comments.

There are four questions worthing considering here. First, is given the nature of the virtual environment of the internet is cyberviolence really a threat or danger? Second, are the respective responses of prosecutors, the government and individual websites warranted and proportionate to whatever threat or danger is posed? Will real-name authentication, which would have the effect of removing anonymous online speech in South Korea, be a threat to free speech? Do we, and should we, have a right to anonymous speech?