Harm-reduction is a communal and cultural process as much as anything else.
I keep seeing harm-increasing and harm spreading behaviors online and in real life. I remember being in New York in the 1990's. People would call you out for doing minor harm, like needlessly holding up a line. Fast forward to 2017, I see a guy at West Oakland do a ridiculous dance standing on the yellow strip to purposely hold up the BART train. No one besides the conductor says anything. Our culture has lost the ability to spread and enforce such norms.