Many users who are fed up with Facebook and want to delete their profiles end up not following through for one simple reason: birthdays.

Indeed, among all of the site’s many features, Facebook’s birthday notifications might be the most invaluable for people who no longer keep tabs on friends’ occasions the old-fashioned way. However, even that innocuous feature poses a safety threat to users, according to security expert Phil Lieberman.

“It’s one of the pieces of information that’s most often used in identity theft,” Lieberman told The San Diego Union-Tribune at a security conference. “Hackers scrape Facebook and LinkedIn for information like that because it helps them to pretend to be you.”

Hackers don’t need much to get started stealing your identity — in fact, just a birthdate and a zip code will suffice. It’s difficult to scrub that information from the Internet completely, but the consequences could be dire if you don’t try.

“Something seemingly innocent, like posting our birthday on Facebook, can provide thieves with just enough information to access bank accounts, credit cards, sign up for credit and more,” identity theft expert Kelly Santos told The Christian Science Monitor in 2013.

To remove your birthdate from Facebook just go to the “About” button, then “Contact and Basic Info.” Then, set your birthdate privacy preference to “Only Me.” While it’s fun to get a rush of Facebook well-wishes on your birthday, it’s even better to secure your online identity.