I've had my rant, and not entirely welcome hitcounter hyperactivity, for today, so I have breathed into a brown paper bag for several minutes before writing this.
This is just anecdotal, but I have noticed that bags of items left (out of hours) outside charity shops often get "raided" by people looking for bargains prior to the charity shops opening them.
I saw one quite lady going through some bags outside such a shop last week.
At the weekend, I noticed that one charity shop had about a dozen bags outside it, all with items left by donors. However, all of these had been ripped apart, as if by rats, by people looking for something for nothing. The resultant mess looked awful.
While not wanting to go into hypertwitch mode to describe my thoughts on the people that do this, it certainly is worth considering waiting for the opening times of the charity shops, before handing over any donations. If you want the goods to go into the right hands, that is.