I am not often harassed by "tin rattlers", indeed I cannot remember it happening at all. There, are of course, people who stand at the exit of supermarkets (in the dry) or in the street who rattle their tins as you walk past and sometimes I give and sometimes I don't. But none have actually come up to me and rattled a tin in my face. I believe these people are unpaid volunteers. [Having, some years ago, collected for charities I like I remember lots of people walking past who, in a miracle of selective sight, seem optically incapable of noticing you. (On one occasion two such myopic passers-by, goint in opposite directions, bashed into each other. I promise you I did not laugh out loud - did smile though].
"Chuggers" I find quite different. They come up and address you in the street (I am not sure supermarkets permit them to trade inside), give you a spiel similar to that you get on nuisance phone calls from people who want to tell you your computer has a virus, and try to get you to instantly provide them with a credit card number so they can take monthly payments - which I never do. I believe most of these people are paid for their work and it would not surprise me to learn that they are on some of commission basis for numbers of punters signed up which would account for their quite aggressive approach.
