@jespah,
when I sign in to Facebook, it also signs in the person with the link I sent. So when I am signed in, they can click the link, click on my name or home page and access all my account information, my private messages, etc... When I sign out, it also signs out the link. It's like the two are synced together.
I can change my password 1,000 times but as long as I use the new password to sign on to my Facebook page, it automatically gives the hyperlink access to my page/account. They would only need a password if they try to sign on when I am logged out
Facebook showed this to be an easy way to send a link of a fb video that you wanted to share with someone who did not have to have Facebook to view the video. It showed it as simply sending the link to that video. It did not mention that your also giving that person access to your page/account!