Lucario1829 Security preview releases are disabled by default. We made the page for opting into it recommend enabling it by having it toggled on by default. Users who have not explicitly set it to either enabled or disabled get a persistent notification each boot opening an activity to choose. If people simply ignore it or switch away from the application, it remains disabled, because the default is disabled. If the value is not explicitly set by the user, it's disabled. It must be explicitly enabled by the user to be enabled. For new users, the page for deciding comes during the initial setup wizard. Prior to reaching that page of the setup wizard, it is disabled. It's disabled by default and therefore opt-in. The menu for choosing does have it checked by default, yes, but it's still opt-in and doesn't get enabled until you accept it. Opt-out would mean it's enabled by default, which it isn't. The releases from the web installer and releases page are regular releases, and security previews aren't enabled until the user explicitly enabled it. Our recommendation is enabling it, so the page for choosing either in the setup wizard or from the notification has it checked by default. It remains off by default for existing installs unless users change it, we just designed a user interface which encourages people to use it.