"Every user would check that option" is obviously incorrect. When given the option not to share information, a great deal choose not to. I won't pull a percenta

"Every user would check that option" is obviously incorrect. When given the option not to share information, a great deal choose not to. I won't pull a percentage out of thin air, but peoples tendency towards "deny" when given the option is the reason for a lot of the dark patterns that exist (e.g. spamming address book permission dialogs, non-compliant cookie dialogs) and for spying as much as possible without permission. Asking permission for things that might be considered invasive is still the ethical thing to do, and in the early days of computing before the profit motive became overwhelming, developers tended to do the ethical thing, unlike today.