It's a vector for identity theft.
My name, and the very fact that I exist are vectors for identity theft. But that doesn't mean I should keep those facts secret either, or that simply attempting to keep them secret will have any effect whatsoever.
Birthdays are one of the absolute worst kept secrets on the Internet. There are entire sites that blab that information to anyone who asks.
You realize your birth date is public information, right?
My name, and the very fact that I exist are vectors for identity theft. But that doesn't mean I should keep those facts secret either, or that simply attempting to keep them secret will have any effect whatsoever.
Birthdays are one of the absolute worst kept secrets on the Internet. There are entire sites that blab that information to anyone who asks.
You realize your birth date is public information, right?