Is it permissible to prevent a family member or friend from accessing pornographic websites on their phone by special means without their knowledge, given the inability to advise them?

Viewing pornographic websites is a great evil and a corrupting disease. Evil must be denounced with the hand; if one is unable, then with the tongue; and if one is unable, then with the heart. If it is possible to block pornographic websites on someone's phone without their knowledge and without any resulting harm, then it is permissible. Denouncing evil has four degrees: the first two are legitimate, the third is a matter of ijtihad (independent reasoning), and the fourth is forbidden. An individual is not obligated to break flutes or forbidden instruments if doing so would lead to greater harm.