My Sister is now 17 years old, but while she was still 15, a then 21 year old began courting her. They went behind my parents back and he actually arranged various meetings with her in which they kissed, cuddled and caressed. Her attitude has changed with us and we discovered various e-mails in which he would incite her to rebel against my parents. Is there any legal recourse that we can use to keep him away from her? We tried talking to him and he never saw anything wrong with it. He is controlling, manipulative and even has control of her e-mail and social media passwords as to not allow any other guys to talk to her.