On the topic of privacy - I find it hilarious when people blow it out of proportion
Don't put any information online that you are not comfortable with. Confirmation emails from steam aside, most of my gmail mail is spam and subscriptions to spam. 110% of my facebook is spam and garbage. I don't even use my real name on fb (I should rename myself btw) nor have a real account. I've taken to untagging myself from my real pictures, thus making it a complete chore to figure out who I am.
I have a quote - why are you putting your visa card # in your profile? you wouldn't do that, so why put other information?