When you type a password into any web form, both Internet Explorer and Firefox prompt whether you would like them to remember your password.
If that's a personal computer, chances are high that you will click Yes and the password is then saved in the web browser.
This "Remember Me" option in web browsers is useful but it actually puts your login credentials at serious risk especially in Firefox.
View stored passwords in Internet Explorer:
Though IE stores your passwords in encrypted form in the Windows Registry database, anyone can easily view your passwords using a free 35kb tool called IE PassView.
The tool automatically displays a list all auto-complete entries saved inside IE. See screenshot.
View stored passwords in Firefox:
With Firefox, it gets much simpler and anyone who knows how to use a mouse can see all your passwords stored inside Firefox.
The route is Tools -> Options -> Security -> Show Passwords. And there you have all the passwords that you ever asked Firefox to remember for you.
Even that short visit to a nearby coffee vending machine could leak your identity as all it takes is few seconds for anyone to view your secret passwords.
To keep yourself safe, uncheck "Prompt me to save passwords" in Internet Explorer and "Set Master Password" in Firefox.