I think there's a security leak in F7. I found out the next thing:

Look at this situation:

There are 2 accounts on a computer, call them A and B. Each account has it's own different password.

Person A starts up the computer and logs in. But at a certain point person B wants to use his account for 5 minutes. So he uses the Fast User Switch. As this happens person A's account stays active. But… person B can switch back to person A's account without entering a password! So if person A is gone for a while, person B can steal his documents, delete files, …

Greetings,

Michaël Vanderheeren