the root of the problem is secular law, which is about "punishment", rather than "restitution". these vandals will spend a week or two in jail, and come out feeling like heroes, for "doing a mitzvah" (sic). in the meantime, the harm to the victim has not been fixed. instead, they should be required to pay (double) the cost of replacing the damaged posters, to the victim, the theatre company, and held in custody, under not so nice conditions, until they pay. and they would have the consolation of knowing that this was done in accordance with torah principles.