Love how a few people are blaming the kid for it. He has autism that affects his judgement. If anything, this is a parenting fail. The mother shouldn't let him do transactions on his own due to his disability, or at the very least should teach him to consult her when wanting to do a transaction. I get the part of teaching him to be independant, but if he has that much money on his account, the least his mother could've done is to supervise his money usage a little bit. While the guy tricking him is a piece of shit, the mother could've tried preventing him from getting scammed by supervising his money usage, or like I said, agree with him to consult her if he wants to spend his money on something. By discussing about the transaction/purchase, the mother doesn't outright tell him to not do it, but could easily detect a scam before anything happens and then teach him why he shouldn't give money to strangers (Or in this case, online "friend")
That being said, I hope the scammer gets caught and punished, but this could've been avoided by some better parenting.