What is a cloaked message in Facebook

A coworker of mine is trying to figure this out and I haven't heard of it before. What is a "cloaked" message in Facebook?

From web app Dan Woodward

• Sounds like a scam-application to me.

  From Andrew Bolster

• I don't think it actually exists: http://www.google.com/search?hl=en&q=facebook+cloaked+message

  From Alex

• Your coworker MAY be talking about a Firefox plugin called CloakGuard. It requires all users to have the plugin installed and allows you to obfuscate certain portions of your content on Gmail, Facebook, and a few others using a password.

  Not sure how well it works and haven't personally tried it. Here's a few videos showing it in action.

  Dan Woodward : This seems like the best answer we found. Not sure I would bother using it, but I'm sure it's for someone.
  From Michael