Love my family, and they are awesome in other ways, but will probably always battle with them over the issues of "stuff" and "waste".
A few years ago, before the show Hoarders, there was a show called Clean House starring Niecy Nash. One episode involved a young married couple and their house, overrun with "treasures" her family kept dumping on them. It sounded as though the family were all hoarders and now that there was new "free" space, they were going to fill it up. As an example, I remember someone had been driving along the highway and had seen a golf bag and stopped, picked it up and brought it to their house. The clubs were all bent and totally unusable. They felt like they couldn't get rid of it because it would be "mean" or "rude". Niecy pointed out that her family was being incredibly rude and presumptuous to foist junk, BROKEN junk, on them and take over their home as a dumping ground. And honestly, the house and yard looked like a dump, a real dump. Niecy basically told them to grow spines and refuse to allow this behavior to continue.
I needed to read this. When my inlaws were here earlier this month, I was "given" six jars of homecanned food. I have no problem with homecanned foods at all, my pantry is full of things I've canned. However, the newest of these jars is from 2011, the oldest, 2005, and that is orange cucumber relish, not something we'd eat at all. The rest of the canned goods are strange food combos or food that I question the quality of before it was canned. We will not eat them at all, I know to be polite (even though they are gone) I will stick them in my pantry and then curse them whenever I can't put something else away, so in the garbage they will go.
So it may not have been garbage they were leaving in my yard, it is garbage they are giving us none the less.