It's not the individuals who broke their window who will be sued. It's the state, county, and/or city/town who will be sued for lack of police protection. Even though the video proved the police was protecting them, if it gets ugly, the Phelps will sue the richest jurisdiction.
Then the response of the municipality should be,"TAKE us to court.We are still within our rights to a jury trial.You'll never get a conviction"
Of course,if the city involved takes the coward's way out and"settles"then they DESERVE to get taken to the cleaners by these sickos.