I haven't thought about it much, but wouldn't this be usefull:
on output event, which triggers when something is sent to the server
NOT byt the user, I know that there's already an event that does that, but by the SCRIPT
one simple use for such event: on *:output:halt - and you're sure the script you downloaded wouldn't send your password

well, for this to work there should be only 1 on output event in all scripts i guess
dunno

just think about the idea