I've had some buyers come to my house or my pole barn for large items, or met off-site. The local PD encourages people to use their well-lit, camera-equipped parking lot for transactions. If a seller gives me a location, I always check it out online. Never had anyone want to meet at a location that seemed suspicious.

Facebook at least gives you the ability to check out someone by checking their profile. I've found things I wanted at a good price, but not even contacted them because their profile screams SCAM (brand new account, no friends, no info, no location, etc).

Had one guy ask what I had in my pole barn. I went into a long explanation of the alarm system that sprays pepper spray as soon as the alarm is activated... He was there with his dad who was laughing his a$$ off and told him that if the place was ever broken into he could expect a visit from the sheriff...