People who leave goods outside charity shops such as this or any of the numerous charity bins without ensuring they are either handed to the shop workers or placed in the bins are, in fact, littering, and can attract a fine under the Litter Act.
However good your intentions may be, you are contributing to the problem.
Ask the shop workers, who are usually volunteers, or any resident who lives near one of these areas how frustrating it can be to have your suburb look like a dumping ground and have constantly to clean up after people who think it is all right to place their unwanted goods inappropriately. Some even use these areas to dump their rubbish.
So please check the Yellow Pages or the internet to find out the appropriate places and times you can drop your goods to charity shops, or if using charity bins, make sure you place items in the bin.