Have these swap meets occurred in the past? and what are people's thoughts on this?

Ive never experienced one of these... Would be a good place to peddle stolen goods imo.

Good idea in theory, but probly a nightmare in practice. As mentioned, how do you trust the sellers of the goods, whether they're stolen or otherwise. It's all well and good to pick up a bargain amp only to find out when you got to hook it up that it doesn't work!