For a long time I have been following your advice with great interest. However, this week I have been talking with some of my less-believing friends and they were surprised to see statistics being so misrepresented on your last column, http://christwire.org/2009/02/is-it-ok-for-my-christian-daughter-to-masturbate/
They seemed to think that you had chosen your statistics in the following paragraph very carefully:
"Studies show that 87% of the women who become prostitutes did so because of unbridled masturbation as a teenager, and over 90% of girls who become pregnant as teenagers did so because of masturbation loosened their morals and made them more apt to engage in unprotected fornication."
I don't believe you'd misrepresent your position as blatantly as they seem to think you have, but when I think more carefully about the facts you present I do worry slightly.
You claim that 87% of prostitutes masturbated, but do not explain how many teenage masturbators became prostitutes.
You do the same with pregnant girls; this does not show any correlation, let alone causation.
Your conclusions from these statements are also on rather shaky ground.
What a shame that such an excellent resource for Christians should be spoilt by such intellectual dishonesty.