When I was a young tyke, there was a chain of ice cream shoppes called "Farrell's Ice Cream Parlors". As did many such businesses, they had a marketing ploy. You filled out a card with your name, address and birthday, and on your birthday you'd get a coupon for a free sundae. Then the rest of the data went to a Bigass Data Company(tm)
Well, a friend of mine really liked ice cream, so he filled out a bunch of cards, with different dates on them, so that he would get free ice cream every so often throughout the year. Worked, too, until all these fake people turned 14 and were ineligible for more goodies.
Comes along our senior year in high school and we've completely forgotten about free ice cream (being distracted by girls or higher mathematics or something). Imagine my friend's surprise when "Andy Aardvark" gets a letter asking why Mr. Aardvark has not yet submitted a Selective Service registration form, as is required by law within 30 days of your 18th birthday.
Don't even tell me how much safer my data is in the hands of the Private Sector. Heck, I have no problem giving the federal government my social security number when asked...they gave it to me first after all. But watch out for them private parties out there. They'll sell your eyes for a quarter point on a loan.