Would posting garage sale signs lead to the perpetrator getting cited for vandalism and criminal mischief (after getting roughed up)?
What exactly was vandalized? No property damage of any kind. How is posting a sign a criminal act?
(These questions aren't really aimed at you, SJ)
Political speech is a more strongly protected right than advertising for commerce. This is the perfect case for the ACLU to take up, if they were really for protecting American civil liberties.