The lesson for anyone in Wisconsin (really anyone in the country) is to always be armed, especially if you're going to protest. Everyone needs to be armed from now on. Whatever you're doing, whether you right or left, wrong or right, you might as well increase your odds of remaining alive.
The lesson should actually be.....if you are going to protest then protest and don't riot. March, carry signs, express you opinions, obey the law, don't attack people and try to kill them. Do that and you'll be fine.
However, a lot of people don't actually give a fuck about the "protest". To them it's just an excuse to tear up shit, get violent, and take out their anger about their failed and worthless lives.
As a result, sometimes they fuck around and find out.