抄録
With regard to “telephone numbers,” for which a request for disclosure of sender’s information newly became possible due to the revision of laws and regulations, I reviewed 41 court decisions that determined whether the revised laws and regulations could be applied to acts committed prior to the enforcement of the revised laws and regulations.
While most of the court cases consider that the statute in effect at the base time of the decision is naturally applicable, there are also court cases that hold that the statute in effect at the time the information was transmitted should be applied.
The reason for the divergent conclusions may lie in the nature of the right to request disclosure of the sender’s information and whether or not to emphasize the disadvantages suffered by the sender.
