Fairly common suggestion for make shift defense against home intruders or domestic violence If sprayed in eyes person is blinded until they get medical attention
People do keep it on hand where I live (in the South) as a sort of quickie self-defense thing. It gives you time to run away, at least, and if you’re armed, it may give you time to get out the weapon.
I’ve never heard of it being used in an attack before, but maybe it has been and the press doesn’t report it. If so, LE need to start training their people. Although looking at how fast the TSA people responded, I’m wondering if maybe they already have.