I found out -its the same with buyers and sellers...... just had some really nasty dude call me up and ask me when he should bring the bike over , for a bike I called about once 2 weeks ago and never said I'd buy, sight unseen. I had never even gone beyond a couple questions - 2 weeks ago!! The guy said he "wanted to plan his day and when could we meet" He was literally stunned when I said never and he started cursing. Click. Probably a criminal. Or maybe just an asshole.
The again I have met some very nice people and had some great transactions off CL. One thing I found out - never ever give them your address. I make them drive to the gas station a block away and call me, then I drive over and if they seem legit I bring them to the house. I used to give directions, but I came home to find them wandering around my yard, only a month late. Funny but those kind of assholes never buy anything, they just bring all their friends to your house to look at your stuff.