Enhanced API Security is a feature that will require calls to all endpoints to be authorized. If desired, please request this with your CSM or the Dynamic Signal Support Team.
Note
A side-effect of having this feature enabled is that when you try to access an in-application display mode post (which would normally be public), you'll get redirected to the login page. The same thing happens to the Facebook crawler, which crawls the login page resulting in an undesirable preview of the login page (rather than the expected content). Therefore, with Enhanced API Security Enabled, in-application posts should not be shared to Facebook.