The word 'hacking' may be confusing for some people. From a technical perspective, hacking a friend's Facebook to post silly things in his name would require access to Facebook's data storage to perform SQL queries to find the person's log-in info. Or, you would have had to pilfer some sketchy website to steal the password the next time your pal logged in. However, a slip-up on your friend's part for leaving their Facebook logged in, well, isn't exactly a hack, but still a much-appreciated prank opportunity. Check out this list of hilarious Facebook hacks left on the walls of unsuspecting users and enjoy some possible inspiration for the next time you get access to a friend's account.