Social networks VS Relationships (what is your view)

i.e facebook,twitter,mixit.migg33 and so fourth.these networks are created to bring people together and closer.Yet is that the case?do they really bring us together?yes but then we have chatrooms and dicet.....where and how does one draw the line?confusing us with real affection and cyber lust?
feel free to comment below and express your view about these social networks.let your view out to the world