At least it's getting used and not going into a landfill. Most stuff (old lamps) can be fixed and reused.
I use to put stuff out in cardboard boxes a few days before garbage day so that I'd feel better about not hauling it to the salvation army.

I wouldn't knock on someone's door if something was in the garbage, I'd just take it. Of course that's only if it was clearly garbage and out at the curb, not hanging out beside their house or in their garden.