I have not owned any. There are kegs legally in private hands of course, keggles are made from them by cutting the tops. But when someone goes to a beer distributor and pays a $25 dollar deposit, they have no rights to the keg after using it. Do they have any markings or stickers on them? If so, and you return them, you may collect the deposit and spend it on brewing gear. I have a wooden beer keg from Ruppert's long defunct brewery, there is no one to return it to. Some of my corny kegs are marked as property of some distributor or other, but they are decades old, and no one uses steel soda kegs for soda anymore. I would just check any markings and do an internet search for my own peace of mind.