The effectiveness of tools like FaceNiff has drastically decreased over the years due to widespread security upgrades across the internet.

Background processes that monitor your device activity.

Modern browsers (including Chrome and Safari) introduced the SameSite cookie attribute. Facebook's cookies now have SameSite=Lax or Strict . This means the cookie is bound to the originating domain. Even if you steal the cookie string and inject it into your browser, the browser will reject it because the "Site" context (IP address vs. facebook.com) does not match.