What is the ruling on trading on the internet by owning an internet café and renting internet lines to citizens, taking into account the possibility of the service being used for unlawful purposes?

If it is possible to control the websites frequented by those in the hall, or if it is predominantly the case that they browse beneficial or permissible sites, then there is no harm. However, if it is highly probable that most users access forbidden websites, then it is not permissible to enable them to do so, based on the Almighty's saying: "And do not cooperate in sin and aggression." Therefore, whoever knows that the internet will be used for what is forbidden, it is not permissible to assist or enable them in it.