My parent , especially my mom , she always tell me to stop doing bitcoin otherwise i will go to jail or doing bad things to social ! I don't get it ! Old generation seem very lack of experience in Bitcoin ! Why they keep telling us to stop when they even don't know how to check a simple email on ebay ! How to explain them guys ?
Like what other said, your parents are trying to protect especially now that internet or online world has made a bad impression specifically to "old generation" as you stated. The thing is to make them understand that it is legal with proofs that truly it is and back them up that the government released a regulation (if your government did so) and support or atleast recognize it which implies that Bitcoin is not bad at all and not a scam. Goodluck!
Actually, depending what he is doing with Bitcoins can put him on the jail. In some countries Ponzi businesses aren't allowed and those who join these schemes can have problems with the law. And we know it's very common on Bitcoin world to join Ponzi and HYIP schemes, especially newbies who are starting their journey here. Maybe there are some other activities forbidden also in some countries that are common on the internet with Bitcoins.
His mother is surely trying to protect him, but if he left Bitcoin because of it he will be losing a big chance on his life... Just make sure about what is allowed and what isn't on the country and be safe.