Shocked and horrified.

I am shocked and horrified. One of my Facebook "friends" has been sexually harassing one of my relatives. The only thing the two have in common is my Facebook page. How did this happen? How could someone that I accepted as a contact, someone I have known in my life's journey, turn into a cyber-stalker and sexual fiend, someone who would go so far as to threaten to pay a visit to this relative if the relative dare tell me that the abuse was happening?
Further, how could this happen to two people on MY "friends" list -- when I am the one who keeps spouting on about how the privacy system on Facebook works well, that Facebook is a safe place for productive and meaningful communication?
First, let me say that I am appalled and dismayed that this has happened. I am absolutely disgusted by the behavior of this acquaintance toward a relative of mine. I would be disgusted if it hadn't been an acquaintance or a relative. The behavior reported to me by yet another relative is rude, lewd, disgusting, and just plain wrong. While I won't comment about possible legal action, the perpetrator is clearly in need of serious psychological counseling. This person, who has a family of his/her own, does know that what s/he is doing is immoral, unethical and flat out wrong. This person would undoubtedly be infuriated if his/her spouse or child was the recipient such behavior. Yet this person has continued to stalk and harass this member of my family.
So, how did this come to be? How did these two otherwise unconnected people ever make contact? Through my Facebook wall. My relative responded to a comment on my wall made by this person from my past. That person furthered the conversation through the Facebook inbox system. My relative responded in good faith; after all, if this person was a friend of mine, it must be safe to continue the conversation. The relative and this person established the Facebook “friend” status between them The conversation was not initially harassing or sexual, but this person became infatuated by my relative.
With “friend” status, more private information is available, including phone numbers and your address – if you are not careful to protect your information. With this information in hand, a person can contact you by phone, by text, by e-mail, and even – if you don’t protect the information – know where you live.
By the time I post this on my blog and in my Facebook notes, I will have contacted the person involved, expressed by disgust and anger, blocked him/her completely from my Facebook account and posts, and told others in my Facebook circle of friends of what has happened so they will be aware of the risk involved in choosing to “friend” someone they have never personally met. And my point in posting this at all is this: Protect you private information on Facebook by setting your privacy settings and being very selective in who you allow into your circle of friends. Learn how to make groups in your friends list and block those who might turn into your stalker.
And to this person who I thought I knew: please choose to get the psychological counseling you so desperately need, confess your wrongs, and make amends.