SF Billboard Ban threatens Local Landmark

As usual, our City's "progressive" laws deliver good intentions with
unintended consequences. Doesn't SF have a separate bureaucracy for
historical preservation?Bernal Heights debates if Coca-Cola billboard is
Ad or History
<http://www.sfexaminer.com/local/2011/02/bernal-heights-residents-debate\
-whether-coca-cola-billboard-ad-or-history>

Why do you believe the consequences are unintended?

I suppose I assume enough good faith to think the authors of the law wouldn't want a historic sign beloved by the neighborhood to be destroyed. Legislation is not known for its flexibility, which I think is one of its fundamental limitations as a means of solving social problems.