I used to think trash around my neighborhood was from just a general mass of people not caring about littering. It sounds like that's what you think too.
Then, one day, I saw a homeless guy dumping every single trash can on the street out completely, tearing open the bags, looking for maybe 2 seconds, and then moving on to the next trash can.
Call me harsh, but that behavior should merit a serious prison sentence. I think people overestimate the damage something like this causes to the environment, but underestimate the damage it does to society and the way people think about each other.