I've given panhandlers money only three times. Once because he told me he was the Devil, and he demanded a dollar. He looked enough like he could be the Devil that I figured "why not?"
It turned out later, when I described him to someone else, that he used to be Jesus Christ for a dime.
The second was a dude who actually said, "Hey, you got some money so I can get some pot?" I figured I'd reward that kind of honesty, and told him so.
The third was an old dude on The Embarcadero with a sign that said, "Help a hungry old goat." I was a handler for my friend, who was in his Krampus costume at the time, so we gave the guy $10, a pair of hand warmers, and a cup of coffee from Starbucks.
He insisted on getting a photo.