[mattmanser]

It also requires that you allow it to then track you all over the internet, associate that activity with your name and email and social graph, and then sell it to advertisers allowing them to target your activity and your friends elsewhere on the web.

[w0utert]

Exactly this. My girlfriend uses the same reasoning to downplay the level of tracking Facebook can do on her. 'Yes I use Facebook, but I don't put any personal information on it, and I have everything set to private'.

The problem is, that after you sign up and enter only your e-mail address, Facebook will fill in all the blanks for you, without needing any interaction from your side...