If I feel inclined to donate to their cause, I always offer to take them to get what they say they need. "I need some gas" okay let's go to the gas station and I'll buy you some fuel. "i need money for food" Okay let's go to McDonalds and I'll buy you a meal. Changes the story real quick in most cases. Some have been in need and i'n glad I could help them, most are not and just looking for drug or alcohol money.