Hacked data on over 553 million Facebook users was leaked online over the weekend, including names, birthdates, a Facebook user’s relationship status, the city where they live, their workplace, and sometimes even email addresses. But the most sensitive data included in the leak is arguably the phone numbers, which are often used for two-factor authentication. And now there’s a way to easily check if your phone number is in the leak—at least if you live in the U.S.
The website The News Each Day has a simple tool where you can input your phone number and see if it’s in the leak. Gizmodo tested the tool against some data from the actual Facebook leak and found it to be accurate. For example, we tested Mark Zuckerberg’s phone number, which is included in the leak. It worked. (We assume Zuck has changed his phone number by now.)
If you’re willing to risk handing over your phone number, all you need to do to check is input your phone number without any hyphens or periods. You also need to include the international country code at the beginning. For example, if you’re used to seeing your phone number in this form, 555-212-0000, you should get rid of the hyphens and add the digit “one” in front.
Using the same fake number above, the number you input should look like this: 15552120000. If you include a variation that’s anything but the string of numbers, the tool will falsely tell you that your number is not included in the leak. In reality, it very well could be.