It is hard not to let one or two bad experiences burn you.
A few years ago I belonged to an MSN quilt group and one of the members asked if I could help her out learning how to quilt. I agreed. She actually got upset with me that I wasn't sending her enough (after I cut all the pieces for her and sent her the instructions on how to piece a simple quilt for her son) but since it was going up to Canada, I said I wasn't going to pay for shipping for the batting and that she would have to go buy some. Anyway, about a month later, she e-mailed me asking for $100 to help them get school supplies for their kids to go to school. I told her I couldn't send her the money (and at the time, I really couldn't!). She got angry and said she knew I could afford to, I just was being selfish. I was appalled. Needless to say, I didn't send her the money and ended up having to block her from my e-mail. The moderator of the MSN group removed her from membership as well because she was soliciting other members for money and fabric.
On the flip side, I have sent out fabric and supplies when I KNOW it will find a grateful recipient who genuinely wants and needs the fabric. I totally believe that when we bless others, we are blessed ourselves.