The Seattle Police Department made news recently when officers decided to start ticketing drivers who honked their horns in support of the Occupy Seattle movement in downtown’s Westlake Park. The Seattle Municipal Code says that horns can be honked only for auto-safety purposes, and under that strict interpretation, several drivers were given $86 tickets.

What SPD might not have counted on, however, is a recent precedent-setting case decided by the state Supreme Court that should void all those tickets. In State v. Immelt, Snohomish County resident Helen Immelt had been ticketed for exacting revenge on a hated neighbor by showing up at the neighbor’s house regularly to lay on her horn.

Immelt fought the ticket on free-speech grounds and lost in a lower court. But the Washington Supreme Court decided that the previous ruling was too broad and tossed the conviction, ruling that deciding where free speech ends and criminal noisemaking begins is too vague for the courts to determine. Seattle attorney Aaron Pelley says that ruling can now be used to throw out citations for Occupy Seattle-based horn-honking (if not for all horn-honking charges). “You can walk in, cite the case law from State v. Immelt which says this is constitutionally protected speech, and move for a dismissal,” Pelley says. “In fighting these cases, I would have made a safety argument, but I’m happy to make the Immelt argument.”

Pelley says he is representing clients pro bono on Occupy-related horn-honking citations. But even without a lawyer, the Immelt precedent should make it easy for anyone to have such a charge quickly tossed—a decision deserving of at least one long toot of appreciation.