Is the owner of a website held sinful for impermissible content (such as images of women or music) on external sites that he directs to, and when does the sin apply or not apply?

Whoever wishes to create a website directory must limit it to permissible websites only, because directing to websites that contain forbidden things like songs and immodest pictures makes the owner of the directory a partner in sin. The Messenger of Allah, peace and blessings be upon him, said: "Whoever calls to misguidance will have a sin similar to the sins of those who follow him." One must adhere to directing to permissible websites only, for the existence of many websites free from religious prohibitions negates the difficulty of this, and the widespread nature of the forbidden does not justify directing to it.