Trust?

I realize a few of my friends trust me, a lot maybe..
I feel so because sometime they need my help to access into the account (Facebook, Email) to help them do something and they gave me their username and passwords.
I feel that these stuffs are very private and confidential.
Even myself, I can't bring to let my friends to know my passwords!
I guess you need a certain trust to the person in order to let them know something that is private and confidential to you right?

However, I don't really encourage people to do so as in giving your passwords away.
Even if you trust the person, one day they might even betray you.?
I am not saying that I will betray my friends.
Its just that if something happen to their accounts, they might think of me because I know their passwords.
As much as I would like to help out, I also don't want to land myself into this kind of trouble.
Well, I guess you all know what I meant.

Hmm.. Its just food for thoughts.