Jar Social Network

I think social network is good because I can contact everybody in this world, I can share my photo with my friends and taged some pictures and I think it's safe , I can make my personal profile to be private. And I can write my opinion on my wall or comment on others wall too. Another thing is I can join a groups on facebook.
However, I think it can be bad because : you can get addict to facebook. You will spending all your day on computer without doing exercise . Such a waste of time!!!