
Social Networks differ from site to site but they all share one very obvious thing in common, they are social networks. Physical social networks and virtual social networks share many similarities but they also have many differences. the main difference being that with one you can actually physically touch the people you are interacting with. The similarities being that you can interact with family, friends, and co-workers in real time.
The pro's of social networks are that you can interact and stay in contact with people in real time no matter where they are, be it around the world or across the street.
The con's of social networks are that some people use them with the intent to harm other people. And is it really necessary to know what people are doing at all time?
Personally I think that social networks are a good way to interact with friends when they are not in close proximity. I certainty don't think that they are evil.
It depends on the information you provide, the material you post, and the people you friend that can ultimately bring you harm. So just be weary of the content you post, and always use common sense