Private Space becomes Public

Our temple online accounts are something I consider private, but our school computers are making them public. Everytime I go to log on to my TUportal account I have the option of logging on to someone else's account- their username and password are automatically stored on the computer. It makes me wonder....Does someone else log on to my account once I log off from this computer? By having access to my temple email account someone can view my cell phone account info, my credit card information, the grades I got last semester, my name and address and a whole collection of personal information about me. Our email accounts tell everything about us. By browsing through my old emails you can also see information about who my friends are, what airline I am flying with and where I am staying in Rome. I always thought that I am super careful and don't put too much personal information about myself on the internet but am actually unintentionally making all the information about me available through my inbox and sent mail.