From a general point of view, nothing is really 'safe' in the world, everything can be dangerous, even Facebook, you can get your account hacked, your personal information misused, your photos stolen, everything could happen, but if you keep focused on what's safe and what's not you wouldn't have a life at all because as I said before there is nothing really safe in this world, what we can do is be cautious with our information, adjust our privacy settings, consider the friends we have, pay attention to new friend requests, think twice before posting something too personal and be aware that problems may happen no matter how safe it seems to be. Have a social life is important but we need to be careful.