Is one who downloads satellite channels that his parents use to follow the news sinful if his siblings use them to watch illicit content?

Your friend should not assist his brothers in haram (definition) by downloading corrupt channels that broadcast evil things, for Allah says: "And do not cooperate in sin and aggression." If he does so, and it results in their viewing of forbidden things, he will incur a sin like theirs, for the Prophet, peace and blessings be upon him, said: "And whoever calls to misguidance, he will have a sin upon him like the sins of those who follow him." He must cancel the channels that contain evil and install beneficial ones, in accordance with the saying of Allah: "And cooperate in righteousness and piety." For it is not an act of filial piety to obey one's parents in disobeying Allah.