What is the ruling on profiting from marketing permissible products, such as mobile phones and cameras, given the strong presumption that some buyers might use them for unlawful purposes, while the marketer does not definitively know the intention of every buyer?

The jurists have stipulated that selling something which can be used for both permissible and impermissible purposes is not forbidden unless the seller knows, or strongly believes, that the buyer will use it for impermissible purposes. This is based on the Almighty's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." The majority of jurists stipulate, for the prohibition of the sale, that the seller must know of the buyer's intention to commit what is forbidden. If the seller does not know or is in doubt, the majority opinion is permissibility. It must be understood that the basic principle in transactions is permissibility, not prohibition.