Facebook

Facebook is a site created by Marck Zuckerberg, and in it is possible to get access in a social net, that are connected people of around the world. If you want to have a facebook you only need a email, and then register in the site.
When you are in the Facebook, you can get friends only if you give them an invitation, because Facebook, leave you all responsabilities of privacity, so you can accept all friends you want, but if you don't accept them, then they couldn't see what are you doing.

In Facebook you can do all activities that they create, like games, but the first one objective of surfers, are get comments of their friends and see their photos, more or less like gossip. So all persons who are your friend are able to see what are you doing when you are connected in the LAN.

I don't recomend you have a Facebook, because it takes you a lot of time, that you maybe could use doing another activity,