This has been my experience with advertising free roosters, young or not.
I was naïve at first but when the folks started asking question of age, size, do they have spurs etc. I became suspicious. I started asking questions and most told me their plans. I got to feed to my snakes a lot.
I worked with a lady years ago whose son had a bobcat. Back then there was no such thing as Craigslist etc but he monitored the local papers and bulletin boards at the feed stores for people who where wanting to give away excess roosters or sell for next to nothing and it was one of the ways he fed the bobcat. I had to ask he threw them into the cage alive.
I have not done it for quite some time. I just man up and cull myself. If I hatched them or brought them onto the property as chicks I'd rather they die humanely at my hands.