To the posters who think that anyone who has a different opinion on the subject is "silly" or "uptight" -
OP mentioned none of these "rules" in the original post. It was that a bunch of kids you don't know show up on your property, put flamingos everywhere, and request money to have them removed before the scheduled date. I have never seen this done in my area, so I had no context and it seemed very odd.
But the main thing is that someone else's opinion that flamingos are cute has no bearing on what I want to happen in my yard. I could have water lines, a realtor coming by to take pictures prior to listing a house, friends coming over for a party, or just sprayed the yard. For all my luck, the Google car would drive by right then, and when I want to sell my house next year, all people would see is a yard full of flamingos when they google the address.
Perhaps unlikely or tongue-in-cheek examples, but I could have all kinds of reasons for not wanting this done on my property (including just not wanting it done). Obviously in certain areas this fundraiser is a common occurence, but as I said, this doesn't happen where I live and might get a very different response. I appreciate OP's further clarification that a number is provided where someone would pick them up quickly.
Would people feel the same way if I paid a religious group to plaster someone's yard with pamphlets? Or to fundraise for a cause you don't believe in? To me it's more about the basic assumption that it's OK to actually be on and do something to someone's physical property like this - even if it's lighthearted and temporary.
Some posters dislike pizza sales, the "panhandlers" at the grocery story, etc. Ironic that IMO, this is the same thing wrapped in pink plastic. At least with the others I can just give a polite yes or no and go about my day - no harm, no "fowl"

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