Hi friends, If you are using internet then you must be having accounts on Facebook or Orkut or Myspace etc. (may be in all :)) My question is: Why you joined social networking sites?
1. Just for fun,
2. To remain in touch with my friends and relatives,
3. To make new friends specially beautiful girls :D,
4. To remain updated about others
Let me guess in most cases it would case no. 2 or 3 (correct me if I am wrong). As far as you are safe at this site its ok even if you are addicted to it. But if you are sharing your social or personal information then be aware before talking even.
Bit Defender did survey on it and found more than 90% internet users share sensitive data within 2 hours of continuous talks over chat messenger or over Social sites. According to Internet World Stats, people are spending increasingly more time online, with global Internet usage up by more than 390% between 2000 and 2009. Over this period of time, the popularity of social networks amplified as well.
They did survey by making a fake profile and sending friend request to more than 2000 users (male and female included age varying from 20-65 of 27 years mean age). After a week, the friendship request form proved very successful: out of the 2,000 requests sent by the test-profile, 1,872 were accepted.
A first analysis of the gathered datasets revealed that usually, on a social network, the first impression counts a lot: a very nice looking young woman will always attract a lot of friends. 94% of the 2,000-user experimental sample accepted to become friends with the test-profile.
Surprisingly 86% of them were from IT field (isn’t it hilarious), and more interesting ,31 % of them were from IT Security field. An industry that has been stressing the risks of using social networking sites for many years. (This really surprised me) Most of them added because of display picture which was of a lovely girl.
The worst thing with social networking site is, after having half an hour conversation with stranger they reveal many personal information like their parent’s names, address, spouse, children names (all these information can be use to crack passwords and in most of the cases it works).
They allow them to see their albums which may be copied for wrong purpose. In addition to that, after a 2 hour conversation, 73% revealed what appears to be confidential information from their work place, such as future strategies, plans, and unreleased technologies/software. The results of this study suggest not only that social network users accept unknown persons in their group just based on a nice profile photo, but also that they are willing to reveal personal, sensitive information after a short online conversation.
This means that social networks serve both as a meeting ground where people can present themselves and communicate, but also as a starting point for a virtual “friendship”, which brings people to divulge too much information because of the illusion of anonymity.
So, from the next time if someone sends you friend request or trying to talk to you over chat messenger, have patience do all investigations related to unknown profile (at least take help from Google) , if you feel O.K. then go on else reject it blindly. Never be too emotional over social sites and don’t reveal such things so easily. It may help them in social engineering and they may harm your system, your bank accounts, your reputation even you. See the images below for detailed analysis: 
Source: BitDefender
Before proceeding further some common question to all readers.