I do not think any one of us new to the term social networks , how many social networks out there ? . And I am sure you belong to at least one of them. When I say social networks there are different kind of networks. Some of them are profession networks such as LinkedIn , and some of them are network for fun (facebook) , some of them to share images (flicker). Not only that number of social networks are going up very rapidly.
If we look at those social networks , different network gather different data from us. If we look at the professional networks they will collect data like places where you have worked , type of the work you have done. On the other hand if you look at fun type of networks , it collects data like what do you like to do at the leisure time , what places you would like to visit and etc... , at the end of the day all those networks collect so much of personal data from you. With knowing or not knowing , we let those applications to collect and share our data. I agree that I am also a member of a number of networks.
Now let's see what are the problem associate with having those personal data for public usage.
First thing is you start to receive a number of unwanted or what we call as junk mail , because someone can find your name and email from those networks and then find the areas your are interested in and then send emails. And we all know what happen when your email address goes public.
Second , from those social networks one can find your friends. And then someone can send emails or photo links as your friends sending to you [A good example is tagging and commenting in facebook]. When you see a mail from your friend saying look at this nice picture , you are most likely to click that link. Then it might take you to bad site and ask your to login to the applications which is similar to the that of your social network home page. Then they can collect your user name and password. This is very risky because most of the people use same user name and password for various places.
Third , say you have a friend call “Foo” in facebook , then that person is not there in your professional network. Now what happen is someone (not Foo) can send an invitation asking adding you as a friend in your professional networks. Since the name is familiar to you , without checking too much you will allow to add that person to your network. Once you allow , he can send request to some other friend of you , then that person will also allow , because he is already a friend of yours. This is often happen in entertaining network like facebook.
I am sure there are enough information out there in various social networks , where someone can collect those information and do online transactions or login into your bank accounts. In my view I think social network help a lot for phishing attacks as well.
One thing to remember is yes , social networks are good and fun as well as help a lot. But there is bad site of that, we need to know what kind of data we allow to share. Specially , when you provide your personal information like birthday , address , phone numbers think twice and provide.