As individuals we can opt out. Its still possible to live a full life in the developed world and not use social networks. Some people may find it harder than others – missing out on event invitations that are only sent on Facebook, for example. Not being able to see your friends photos because they’re only posted to Facebook. Not being able to join conversations on Twitter. But for now there are sufficient alternatives for most of us. As with smoking, it’s easier to not start using the social web than to stop. Once you?ve signed up the cost of leaving increases with every friend you make, every photo you post, every tweet you send.