Researcher finds a way to Delete and Modify Facebook Messages Sent to Other Users

The program is only as good as the programmer. A true hacker tends to be many things including a very skilled programmer. They will take the cool features of a program that make it so user friendly and turn it against the host and the end users. Ever hit a hyperlink and your face book account pops up. You have just been doxed, or documented, the entity on the other end no knows who you are.
A very skilled hacker will follow you right to your IP address and learn all there is to know about you. I have seen it done.