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.
I think it's perfectly fine to be cautious, otherwise you would be putting yourself in peril for no good reason. It's not like if you are in danger, the food you share tastes better or something.
We can always find a reason to be cruel. Being kind--that takes a bit more out of us.
the right path is never the easy one...