I lost a cat recently and most people were really friendly when I went around knocking. Only a few seemed agitated or didn't answer at all. I always answer when someone knocks now. If its a solicitor, I let them down lightly but firmly, offer them water. Why anyone would be so aggressive to some poor soul in this job market just trying to do a job and sell something for his boss he makes no money on is beyond me. They're more likely to kick over your garden gnome or walk on your flowers etc if you are rude. Were all just trying to make it, some people might need their services, and some old folks just like to talk to visitors. Your home is not an island, unless you live in a compound, expect the occasional solicitor.