A. The Defendant’s act of mistake of facts and misapprehension of the legal principles is a justifiable act provided for in Article 20 of the Criminal Act, and thus, it is dismissed of illegality or there is no possibility of criticism.

B. The lower court’s sentence of unreasonable sentencing (three million won of fine) is too unreasonable.

2. Determination

A. As to the assertion of mistake of facts and misapprehension of legal principles, "act which does not violate the social rules" under Article 20 of the Criminal Act refers to the act which can be accepted in light of the overall spirit of legal order or the social ethics or social norms surrounding it. Whether certain act is justified as an act that does not violate the social rules, and thus, it should be judged individually and reasonably by considering the specific circumstances. Thus, in order to recognize such legitimate act, the following requirements should be met: (i) legitimacy of the motive or purpose of the act; (ii) reasonableness of the means or method of the act; (iii) balance between the protected interests and the infringed interests; (iv) urgency; and (v) supplementaryness that there is no other means or method than the act (see, e.g., Supreme Court Decisions 2003Do300, Sept. 26, 2003; 2008Do6999, Oct. 23, 2008); and (ii) the defendant's act that the court below lawfully accepted and investigated the contents and frequency of the text message of this case cannot be justified.

B. We examine the argument of unfair sentencing, and the crime of this case is committed.