No, I don't think birdshot would necessarily strongly discourage aggression. If the crowd is large enough it might incite them to charge you. If you're bringing firearms into the mix, even if only with birdshot, you're talking about expanding the scope into deadly force scenarios. Birdshot is not appropriate for that.
So that brings a question to mind. Exactly what do you think is your responsibility in stopping this lawlessness? You're not the law. You have a right to protect yourself and people/property within your sphere, including lethal force if the threat rises to that level. So I'd say when the "lawlessness" reaches your house, your neighbor's house, loved ones, business, whatever, you do what you have to protect that scope of things. Beyond that it's not your gig. Not yet anyway. I'm not going to gear up and patrol some statue downtown to protect it. Keeping the peace is still the job of the police and if they're not asking for citizens to volunteer to come out and help, then just stay home and protect you and yours if it comes to that, with the appropriate force needed. As far as it becoming a citizen's job to help keep the peace, we ain't there yet.
