They are scammers, IMHO. I have heard many sob sories and gotten burned often enough, I verify facts first. No money is given or anything that could be turned into cash. food will be given or directions to a shelter that will help them if they want help.
I don’t by any means do an exhaustive background search on people who ask me for help (usually through church), but I can usually profile a person’s situation based upon their age and biographical information (I don’t ask invasive questions, but I usually try to learn a bit more about them through asking them about their life. The more they talk the easier it is for them to get tripped up in an inconsistency if they’re lying).
I never give money either, but I will give food and shelter if I can. I have housed some homeless people at my place for a few days (I’m a big guy and single so I can take care of myself if they act up).
I personally don’t care if I get burned. The most I will lose is a sandwich or two I gave. It’s the people who think they can get by through manipulation that will get hurt in the long run. I’d much rather someone who is actually starving eat than worry whether someone is going to be demotivated to work because he got one free meal from me.
I agree with the tenets of that site you linked to. Sounds solid and nonjudgmental.