Years ago I volunteered at a community outreach center that was run by a nun. She was amazing. Had worked all over the world helping people. I never met a kinder soul (except my mother). However, she had a rule. She never gave charity to someone who was begging on the street. She didn't know what they would do with the money (buy liquor?) or if they were truly needy. She used legitimate outlets, such as our outreach, to give.
I love that woman, but disagreed with her on that. I figured, even if I was scammed by a street beggar, so what? Nothing wrong with my generous act. The bad is all on them. Their problem. By turning away though, I may be turning from someone truly in need.
Let me add, I am always cautious in giving to random strangers, if I do at all. I never get close enough for them to harm me. I may reach through a car window, for example. This may be rude, but it is effective.
We can always find a reason to be cruel. Being kind--that takes a bit more out of us.
RE: Empathy is a sin now...