No, you are just not allowed to use the high-power scam flags -- intended mainly for punishing people, not really for preemptively warning about scams -- without first being scammed. You can still use the newbie-warning flags and negative ratings, which have plenty of warning power.
I suppose we
did want differing degrees of severity in regards to negative feedback. I'll have to give this some more thought and form a more substantiated opinion as discussion develops.
Is there any message indicator for when a user PMs a flagged user? I know that some users have tried to sneak their way into scamming others in sections that hide trust ratings (and now flag markers).