What are the bad effects of social networking sites(such as Facebook, twitter,etc.) to our health?

[RosePose]

Well, you'll get dependent. For example my friend which started to play facebook games,got dependent by a game, and when I wanted to talk with her she ignored me.
Otherwise you might have posted an unwanted picture and someone could've seen it and forward it. Then you'll have a real problem, because you'll be depressed.
Physical, oh well... after you've got dependence you'll be blocked somehow and you wont practice sports, you wont live healthy because you will also be too lazy to cook and start eating snacks so often until you'll gain weight. That's what happened to my friend and now she has to work really hard to get her health and body back.