Years ago, I was purchasing something at a shop, and noticed a large "Donate to Charity X" sign at the counter. There was, unusually, no indication of what Charity X was for, just lots of pictures of smiling people. I asked about it to the gentleman who was working at the till. He explained that the charity was a con, gave me some basic information on how it operated, and implored me to do my own research and not just take his word for it. I then asked why he would have donation containers for Charity X placed so prominently. He said it was so that people would ask and he could inform them of the scam. Several of his family members had lost quite a bit of money on it, apparently.
I looked it up and it seems like he was right. I saw similar donation tins at other places and avoided them. A few years later, the "charity" was shut down for its less-than-legal practices (stealing the bank account information of people who donated, for one thing).