The judgment of the court below is reversed.

Defendant shall be punished by a fine of KRW 300,000.

The above fine shall not be paid by the defendant.

1. Summary of grounds for appeal;

A. Legal reasoning is that the defendant's act of hiding a banner of the victim is an act aimed at defending the present infringement of the defendant's wife's reputation, which is either a legitimate defense or a legitimate act that does not violate social norms and thus, the illegality is excluded.

B. The sentence of the lower court’s improper sentencing (an amount of KRW 500,000) is too unreasonable.

2. Determination

A. As to the assertion of misapprehension of legal doctrine, a crime of damaging property is established when a special media records, such as another person’s property, documents, or electronic records, are destroyed, concealed, or otherwise impaired their utility by any other means (Article 366 of the Criminal Act). Here, where the utility is impaired by any damage or concealment, it includes not only cases where goods, etc. cannot be used for the original purpose, but also cases where goods, etc. cannot be used for the original purpose, such as temporary goods, etc. are created without any specific role (see, e.g., Supreme Court Decision 2016Do9219, Nov. 25, 2016). To be recognized as a legitimate act as a ground for excluding illegality, a requirement for the justification of motive or purpose, reasonableness of means or method of act, balance between the legal interest and the legal interest infringement, and balance between the two means or methods other than the said act, and the balance between the victim’s legal interests and the legal interests protected by the evidence duly adopted by the court and the victim’s self-defense should be met in light of the following evidence.

Therefore, the defendant's act cannot be seen as a legitimate act or a legitimate defense.

Therefore, the defendant's above assertion is without merit.

B. Regarding the unfair argument of sentencing