I support fundraising efforts of many organizations but I have little tolerance for beggars. Fundraisers that are organized, advertised and have a purpose are always more successful than panhandlers or folks with signs on the side of the road. I hate to be approached by a stranger when it's obvious to me that they're going to ask me for cash. I get particularly perturbed when they approach me in my car at a red light where there is clearly no way for me to escape.
I remember, as a child, that the local American Legion (VFW) held Poppy Days where volunteers would give away tiny artificial flowers, in exchange for donations, to wear in honor of American veterans. They would approach cars at stop signs and red lights and try to give the driver a poppy in exchange for a donation. My parents and grandparents would get a poppy early in the morning and attach it to the driver's visor in the car so that, when approached again, they could point at the poppy to indicate that they had already donated.
I find it intimidating when a crew of men carrying five-gallon buckets strolls through traffic holding out their buckets to collect cash. Sometimes, they don't even have a sign or any indication of why they're collecting funds.