Is it permissible to download TV series or movies shown on television from the internet merely for viewing without selling them? And is this considered theft, or is it permissible since viewing them is available via television?

If movies and TV series are free from religious prohibitions, then it is not permissible to download them except with the permission of their owners or with knowledge that they do not object. This is due to the impermissibility of infringing upon the material and moral rights of others, as copyright and patent rights are protected by Islamic law.