Is it permissible to benefit from explanation videos stolen from a lecturer's personal computer, when the owner does not forgive whoever watches them? Does the ruling on recording lectures without the owner's permission apply to this situation, and would I bear a sin if I were to adopt the opinion of those who permitted it?

We have previously clarified in fatwas the impermissibility of this, based on the preponderant opinion that intellectual property rights of individuals and institutions must be protected. If someone has been given a fatwa (definition) by one whose knowledge and piety they trust, then there is no blame upon them for following it. However, it is not permissible to pick and choose from the sayings of scholars based on caprice and to seek out concessions. Indeed, some scholars, including Abu Ishaq al-Marwazi and Ibn al-Qayyim, considered whoever does that to be a sinner (fasiq). Scholars have deemed wrong whoever takes this path. Al-Shatibi said: "One should not pick and choose, because in picking and choosing there is a dropping of responsibility. And if we give the followers the choice to follow the madhhabs of scholars, they will have no reference point other than following desires and caprice in their choices, and because the foundation of Sharia (definition) is based on a single قول (statement/opinion), which is Allah's ruling in that matter."