Barrett 50 cal.
Blow off a,leg or more.
The anarchists want another Kent State. We should not give them what they want. Thats why I like the Israeli approach. Use a low-velocity .22 round fired from a silenced, bolt-action rifle. Somebody throws something potentially lethal, he gets shot in the knee.
After seeing a few of your buddies mysteriously get shot like that you just might retreat to your moms basement for the duration.