I have "remember me" turned on so I can post on wrox without logging on. If someone sits down at my workstation, they could post as me, but they can't change my information without knowing my password.

Even though I am a moderator and already logged in, I can't make forum changes without entering my password for the same reason. It's a security measure.

If you shop on amazon you see the same procedure. It seems to work for them ok.