I donated to WWP a couple of times. After I got some expensive (but worthless) crap in the mail begging for more money, I wrote them a letter asking them nicely not to waste the money I gave them sending me crap to beg for more money. I told them I'd donate more if they stopped, but if not I wouldn't send more money to be wasted. Several years later I'm still getting expensive crap in the mail from them begging for more money.
Sadly enough, I've had the exact same experience with CAF. This is why when I do donate money to places, I do it anonymously and with cash. I hate these places spending 10 times what I donate to hire people to pester me for more. Between CAF and WWP I suspect they have spent 2-3 times what I donated just on trying to get me to give them more.