This past weekend, I volunteered at our library's used book fundraiser. I was tidying books when I heard a young man say, "Can I just take this?" He was holding a paperback book priced at 50 cents.
I could see that the poor lady working the cash table was wavering. The young man wasn't threatening, and in fact asked quite pleasantly, but he was also enormous and kind of looming over her. She said, "You mean you don't want to pay?" He confirmed that this was the case.
Now, pre-EHell, I might have just let him have the book. It was near the end of the day and we donate our leftovers, anyway. But there were several other customers watching to see what would happen, so I thought of you all standing behind me.
It worked! Just plain NO. He put the book down and wandered away. No drama.