Quoted from mattosborn:If you put it on Craigslist, don't list it for free.
Totally agree. I tried this once (not with pinball) and won't do it again. The crazies come out of the woodwork for anything free. Put a price on it, any price, to keep the nutjobs away.
If you insist on giving it away for free, put it on the curb or in a public place like a park, post on CL where it is and that is it free, then remove the ad as soon as someone picks it up.