For as long as there has been humans, we have been trading goods/animals. It's not going to change any time soon. If someone can no longer care for a animal anymore I see no problem with them using Craigslist as a tool to find a suitable home. The problem is nine times out of ten when you see someone looking to trade a ball python for let's say Xbox or computer, it some spoiled kid who "needed" a ball python while at the store. Now 6 months down the road the new has worn off and the kid is no longer interested. I believe it's the parents job to put their foot down and teach the kid about responsibility and commitment.