Generally, data from AT&T customers go directly to Facebook's network provider, but due to a routing mistake, traffic first went through China Telecom followed by SK Broadband in South Korea before routing to Facebook, IDG News Service reported.

This means that if you were among the customers affected and you did not have encryption enabled, it's possible that network operators in China and South Korea could see your Facebook data.

Such data possibly includes session ID information, personal information, e-mail, photos, chat conversations and an idea of who a person knows via their Facebook profile, the stated. Security experts do say that it is unlikely that those countries did anything with the data, however.

One way to prevent this from happening to your account: Enable HTTPS.

In January, Facebook the HTTPS feature to all browsing done on the site, but it's opt-in an not automatic setting. Previously, Facebook used HTTPS only when you entered in your password. You can see you're browsing securely by the green address bar that appears.