@Digiplace, I agree that it is pretty silly that any user can see your personal files, regardless of the history of UNIX, there are ways to keep your files private however by using enryption
Encrypting home directories allows you to keep your files private. Without the proper authentication, unauthorized users will not be allowed view or access the content stored in your home folder.
To get started, go to Applications –> Ubuntu Software Center.
Then search for and install ‘ecryptfs-utils’
After installing, ‘Encrypt home folder’ option should be enabled when creating new users.
If a user account is already created, and it’s not encrypted, go to Applications –> Accessories –> Terminal and run the command to encrypt an existing account.
sudo ecryptfs-migrate-home -u USERNAME
Replace USERNAME with the username of the account.
After encrypting an existing user directory, allow the user to login immediately before restarting the computer.
When the user logs in, he/she must click ‘Run this action now’ to create a passphrase (password) when prompted below.
When everything works ok, go to the /home folder and delete the temporary folder created for the user. If everything didn’t work, then restore the user’s home directory. But remember, a user must be logged out before you can encrypt his/her home folder.