I once had a guy grab a free Amiga 500 with hard drive sidecar off a freecycle offer minutes before me - even though I was a regular Amiga user and he wasn't. He just grabbed it from the owner because it was something free and he wanted to fool around with it to see what it was. I appealed to the owner that I was an actual Amiga user but I accepted it as "fair is fair" - this guy beat me to the punch.
But then after a week had passed the guy who received the free Amiga 500 with hard drive got bored, or realised he couldn't actually use it. He then e-mailed me and offered to sell it for me for $35 or he was going to put it out with the garbage (destroy it).
I bought it from him just to save it --- but I'll never forget what a pricky thing that was to do.