As the internet media has become more widely used over time, public opinions formed by internet discussions affect political and social issues more critically. While the internet space guarantees equal status for every participant and equal opportunity in terms of freedom of speech based on anonymity, baseless rumors, personal defamation, and privacy invasion against particular individuals and groups are more likely to happen rather than in the face-to-face offline communications. In order to prevent this undesirable effect, the South Korean government implemented Real Name Verification Law in July 2007 by which discussion participants should pass verification process in order to express their opinions in most websites.This study examines the effects of Real Name Verification Law in several aspects. By applying content analysis to abundant data of postings in a leading discussion forum that is subject to the law, the results suggest that Real Name Verification Law has a dampening effect on overall participation in the short-term, but the law did not affect the participation in the long term. Also, identification of postings had significant effects on reducing uninhibited behaviors (swear words and antinormative expressions), suggesting that Real Name Verification Law encouraged users' behavioral changes in the positive direction to some extent. The impact is greater for Heavy User group than for Light and Middle User groups. Also, discussion participants with their real names showed more discreet behaviors regardless of the enforcement of the law.By analyzing the effect of this policy at the forefront of internet trends of South Korea, this paper can shed light on some useful implications and information to policy makers of other countries that may consider certain type of internet regulations in terms of privacy and anonymity.