Is downloading digital materials, such as programs and movies, for free from the internet, while knowing the financial harm it causes their producers, considered theft?

It is not permissible to copy or download useful programs without the permission of their owners, because it is an infringement on the protected rights of others under Islamic law. As for films and TV series that contain forbidden elements, they have no sanctity, and the permission of their producers is irrelevant. It is not permissible to watch them, and a Muslim must change this evil if he is able.