[slackoverflower]

I can understand Facebook knowing what you look like from pictures of you other people upload and your email from others connecting their Gmail address books. How will they know your birth date though?

(FYI, they probably know your phone number and who you made phone calls to, when, and the durations for the last 5 years)

[inlined]

Am I the only one who puts friends' birthdays in their contact card? I assume birthdays come from the same phone number slurping.

[lostlogin]

Every year someone shares the fact its my birthday on Facebook. Combined with my physical address from peoples contacts I’m pretty sure there must be complete profiles on many non-users. Slackoverflower, would call duration come the app on Facebook users phones, and knowing who call were to and from?

[wyclif]

One of the first pieces of info FB asks for is your DOB.

[LiquidFlux]

lostlogin mentioned he had never signed up to FB