The vast majority of people on the planet aren't enough to stop a person (regardless of their ideological beliefs) from threatening, beating, and murdering people in a free society.

In order to actually stop people from doing those things, society would have to give up a lot of freedom to prevention through force ("stopping"). In a free society, the focus is usually on prevention through dissuasion (influence) or through reactive means (punishment, rehabilitation).

What are your thoughts on how society could physically prevent these actions while maintaining freedom for all its citizens ?