These Proud Boys are very fighty, but not very smart.
These Antifa-tards have two security blankets that embolden them: Anonymity and the electronic pacifier. Strip them of both, and watch their courage evaporate.
Many of these black bloc-types have an ironically fetishistic attachments to their bourgeoisie smartphones, which they use to record/stream their criminal activities.
A solution that would be both financially and psychologically damaging is spraying their helpfully exposed electronic devices with water, or hitting the lenses of their phones/cameras with spray paint. Without the warm, emotional protection of a screen and a thousand shrieking Twitter drones for support, would leave them feeling exposed and vulnerable, like most social media addicts.
Second, and more tricky, is stripping the black bloc of their anonymity. This would require actual teamwork and coordination between three-to-five people, to isolate and restrain an Antifa, strip their mask, photograph them, and then kick them loose, while at least two people screen the exposing operation from interference by fellow commie drones.
Exposure is less of a fear for the lumpenproletariat members of antifa, the starving artists, the meth addicts, and the barista-philosophes who are likely losers anyway and have no social relations worth damaging, but for the bourgeoisie beckys, trust fund teddys, and NGO nancys, losing their veneer of respectability would be enough to convince them that their nights are better spent at home.