This incident is resolved. All advisor access has been restored, and no data was lost, altered, or exposed at any point. Notably, the root cause was a permission change that over-indexed on security controls. the rules erred toward locking data down rather than opening it up, so the failure was one of over-protection, not exposure. We've since tightened our testing so access changes can't have this unintended effect again. We apologize for the disruption.