If the police don't stop them a Bernhard Goetz type will.
https://en.wikipedia.org/wiki/1984_New_York_City_Subway_shooting
"
Bernhard Goetz shot four alleged muggers
[1][2][3][4] on a
New York City Subway train in
Manhattan on December 22, 1984. He fired five shots, seriously wounding all four men.
Goetz surrendered to police nine days after the shooting and was eventually charged with
attempted murder,
assault,
reckless endangerment, and several firearms offenses. A jury found him not guilty of all charges except for one count of carrying an unlicensed firearm, for which he served eight months of a one-year sentence. In 1996, one of the shot men, who had been left paraplegic and brain damaged as a result of his injuries, obtained a civil judgment of $43 million against Goetz.
[5]
The incident sparked a nationwide debate on
race and crime in major cities, the legal limits of
self-defense, and the extent to which the citizenry could rely on the police to secure their safety.
[3] Goetz, dubbed the "Subway Vigilante" by New York City's press, came to symbolize New Yorkers' frustrations with the high
crime rates of the 1980s. He was both praised and vilified in the media and public opinion. The incident has also been cited as a contributing factor to the groundswell movement against urban crime and disorder,
[6] and the successful
National Rifle Association campaigns to loosen restrictions on the
concealed carrying of firearms.
[7]"