They're being prosecuted for smirking at cops while destroying pro-cop signage, which can be read as assault. Ask yourself whether in today's age someone could get away with destroying an LGBT sign amidst a pro-LGBT protest, while staring down LGBT people, and get away with it. I don't agree with where the standards are, but most people would observe that this is the standard. Whatever anyone's personal rationalization for preferencing one group over another, in this type of enforcement, it is immaterial as far as the criminal code is concerned. There are no marginalized group allowances for assault.