To the best of my knowledge, religious charities are perfectly happy and able to collect money from anyone; they don't tend to ask what one believes in. It's rather sickening to think someone was actually small minded enough to even try to calculate what overall proportion is donated by atheists to charity.
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Joe - sorry to mess up your Sundays ;-)
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McGrath - "1+1=3 is equivalent to 3 - (1+1)= 0 or 1=0"
Dammit, you've proved I have to be reincarnated, you swine.