Login facebook on share computer

First thing need to know, DONT TRUST ANYONE. Even your girlfriend. heheh..
When we submit or sign any forms such as login form in the browser we will leave autocomplete on each form. This means that email and other information will be stored on a shared computer.
And how can you does not see that email in the autocomplete form like facebook login? First you need to know your username. You can go to account setting to see your username or just click your profile.

Is this your profile?

If so your username is "zuck" and your facebook email is "zuc...@facebook.com". You can try send email to your facebook email. And you can use this email to login your facebook account for security reason. Or you just type your username like this.

Now try it login with your username. More security less hackers.