Messrs. Mémoli were convicted occurred in the context of a dispute between private individuals concerning matters that, possibly, would only affect the members of a private mutual association, without any indication that the content of this information would have any relevance or impact that would go beyond the Association and be of significant interest to the rest of the population of San Andrés de Giles. To the contrary, according to the case file, the accusation of fraud filed by Messrs. Mémoli owing to the “case of the burial niches” was examined by the court and, on June 6, 1990, the judge hearing the charges dismissed the case understanding, among other matters, that the accused had been acting in good faith, and, at that time, no patrimonial damage had been verified (supra para. 70). In parallel to this criminal accusation, Messrs. Mémoli filed a complaint before the National Mutual Action Institute (INAM) asking it to investigate the Italian Association and its Management Committee, among other reasons, for the supposed fraud committed in the case of the burial niches. In June 1991, the Directors of INAM issued a decision in which it was considered that, in the matter of the burial niches, no offense had been committed, but that the Association should draw up regulations in this regard to be approved by INAM (supra para. 71). 147. Consequently, the facts of the instant case do not reveal that the information contained in the statements made by Messrs. Mémoli is of public interest. Even though certain information concerning private individuals or organizations may be classified as information of public interest, in this case two domestic courts analyzed and rejected this argument, and did not consider it a sufficient reason to justify the defamatory or derogatory statements made against the reputation of the complainants (supra paras. 83 and 88). In addition, the Court underlines that, a judge of the Supreme Court of Justice of the province of Buenos Aires ruled similarly when disallowing the application of the new criminal definition of defamation to Messrs. Mémoli (supra para. 94). Referring back to its consideration on the impossibility of acting as a fourth instance (supra para. 140), the Court does not find it justified in a case such as this one to substitute or annul the decision of the domestic courts in this regard. Moreover, the case file shows that the specific matter of the burial niches, which would allegedly be of “public interest,” was examined by the courts in an independent proceeding, as well as by the supervisory entity of mutual associations such as the Italian Association. 148. Consequently, in keeping with the circumstances of this case, the protection of the complainants’ right to honor and reputation is a legitimate framework for the proceedings in which Messrs. Mémoli appeared, and the Court does not find that the reasoning set out by the Argentine judicial authorities in their decision determining the resulting liability of Messrs. Mémoli violates the Convention. 149. Based on all the above considerations, the Court concludes that the subsequent imposition of liability on Messrs. Mémoli for the exercise of their freedom of expression was established by law, respecting an objective permitted by the Convention, and was not manifestly excessive or disproportionate, given the circumstances of this case and the analysis made by the domestic judicial authorities. Therefore, the Court considers that Argentina did not violate Article 13 of the American Convention, in relation to Articles 1(1) and 2 of this instrument, to the detriment of Carlos and Pablo Mémoli. B. The alleged violation of the principle of legality and retroactivity B.1) Arguments of the Commission and of the parties 150. In this case, the representatives argued that, following the amendment of the law, which “eliminates the punishment of imprisonment for anyone in case of defamation,” Article 9 of the Convention was violated “by failing to apply the most favorable law for the Mémoli,” considering that “[the] punishment had concluded.” They stressed that “the civil case is based 58