The legal regulation about the derivative(or secondary) liability of OSP(Online Service Provider) is briefly divided into two parts, liability requirement and liability limitation requirement. In the OSPs’liability requirement portion, Korean courts in Sori-Bada cases has pointed out that joint tort-feasors rule in the clause (3) of article 760 of the Korean Civil Act should be the statutory ground for OSPs liability requirement. Korea Copyright Act has also the article 104 which is a peculiar and even weird provision. It imposes the duty to implement a specific technology measure upon a so-called specific type of ISPs and therefore the article can be another statutory ground for OSPs liability requirement. Moreover, when interpreting the article 104 in the preliminary injunction cases related to Sori-Bada version 5, the Seoul High Court concluded that P2P service providers should adopt so-called the positive filtering system. At first, it seems to be more reasonable to rescind article 104 in future amendments of the Act. It’s because the scope of article 104 is so ambiguous that it may be improperly expanded to almost all OSPs and the article 104 creates unnecessary anti-market manipulation by government. Second, the Seoul High Court’s position is unreasonable. It’s because the liability limitation clauses of Korean Copyright Act are basically based on negative filtering principle, and so-called the positive filtering system is not consistent with Korea-US Free Trade Agreement and the development of filtering technology is not perfect enough to enforce the adoption of the technology. Turning to the OSPs’liability limitation requirement, article 102 and 103 of Korean Copyright Act sets up a liability limitation requirement similar to the Notice and Takedown procedure in the DMCA. It would be appropriate to amend the act in following 2 ways. At first, the Korean Copyright Act had better implement the specific requirement according to the type of information technology, such as caching, hosting, search engine, etc. even though the present act has only a uniform immunity requirement for all type of OSP. Second, the effect related to OSP’s immunity is now no more than discretional mitigation or exemption and should be changed to mandatory exemption. The legal regulation about online service user’s direct liability includes two main issues; Users’ fair use right and the criminal penalty for direct infringement. At first, the statutory and more comprehensive provision of fair use for individual users should be added into Korean Copyright Act, to keep the balance between copyright owner’s protection and the others’ fair use right. Second, the criminal penalty for users’ copyright infringement should be restrained from the rampant misuse which even caused one Korean teenager’s suicide. The new proposal in 2008 by government to amend the present Copyright Act seems to be inappropriate because it is only based on excessive administrative opportunism which would result in excessive restriction on OSPs and severe legal vagueness. Rather, it would be better for the legislature to promote the cooperation between thecopyright owners and OSPs. As anexample, the system similar to the subpoena in DMCA can be establishedin Korean Copyright Act if it will be carefully managed by Korean judicial branch.

O.S.P. shall be criminally liable for offenses committed in cyber space on condition that it could be aware of its occurrences nevertheless nothing is taken expected elimination measures technically by itself. In principle, a professional person who manages its cyber space may suffer punishment and then a company that hires him suffer punishment as prescribed by penalty against employer and employee. O.S.P. could receive a criminal penalty for a crime omission as in the following conditions, first, it has found offenses committed in its cyber space or has not found it because of gross negligence, carelessness by O.S.P., second, O.S.P. have a technical skill and system for expected prevention or elimination a crime happened in cyber space but it didn’t do anything. A willful negligence by O.S.P. may be sufficient for criminal responsibility. The judgement as aforementioned cast a long shadow to us because it has set up the condition of O.S.P.’s criminal penalty in other words, possibilities of awareness, technical prevention, expectation for elimination illegal situation in cyber space etc. It is significant that O.S.P. could supervise and control its cyber space as a dangerous factor connected to offenses. However it feels lack of logical reasoning such like that. Now, we should fully discuss the matter that the building measures of prevention adverse effect by cyber space. The responsibility of O.S.P. should be imposed stringently than ever because offenses in cyber space could be occurred under unsuspected, usual time as a result damage may be very serious, mortal to a personal victim.