When Did Slander Become Acceptible

Over the last few months I have seen the number of cut and paste Facebook statuses of "send this to all your friends" spam spike.  Lately I have seen several of these come around, "DO NOT ACCEPT THESE 4 AS FRIENDS, _______, _______, ______ AND _______ THEY ARE HACKERS, TELL EVERYONE ON YOUR LIST BECAUSE IF SOMEBODY ADDSTHEM, YOUR ACCOUNT WILL BE HACKED TOO. COPY THIS TEXT TO YOURPROFILE... DO NOT BE LAZY, PLEASE POST TO YOUR WALL"


Several things make no sense about this:

1. Why would you give strangers access to your personal information?  That is one reason people started using Facebook was become it was private and only people you choose can see your stuff.
2. If someone tells me that one of my neighbors is a pediphile with no substantiating evidence other than someone told me and told said to tell everyone I know,is it now okay for me to spread it around?
3. By labeling the person as a hacker can they really get into your computer by adding them as a friend on Facebook?