My brother seems to not care about his online privacy. He registers to services too easily without pondering, he’s not outraged we need a fucking account to use a vacuum cleaner, it seems he doesn’t care about all the potential risks of having videos of our indoors saved in a cloud. I don’t have strong arguments to convince him that privacy matters other than “if someone gets that, you could be in trouble” and “it’s like having someone watching you h24” and so on. How can i persuade him?
You don’t
Privacy is something that is fairly personal and different for each person. Trying to force it one someone is going to end badly and will not help at all.