Although this is not advisable, you can do this by finding one of their friends that does not have a facebook default profile picture. This will most likely be a person that does not use facebook very often. What you do is create a new facebook account with the exact same name as the profile that does not have a default profile picture. Once you have created that new account, go and add about 20 of your victims friends. Since they will most likely be mutual friends with both your victim and the account you are creating, they will most likely add you. Now that you have an account that you know is one of your victims friends and you have about 20 mutual friends. Add your victim and tell him or her that this is your new facebook account.