AUTHENTICATED_USER is not reliable! [Was: [Zope] become user (su inside Zope) - pretend to be another user]

[Jens Vagelpohl]

> Why is everybody so obsessed with AUTHENTICATED_USER? This variable is 
> not suitable for anything deserving the name "security". It is NOT 
> SAFE to assume that it will contain anything useful.

Amen to that.

jens