Hi there!
Your question asks who does God cast to hell.
The answer is the people, who are of course sinners, and they don't want to repent. Everyone are sinners, and if they repent then they won't be cast to hell. It is not hard for God to take this action. His word is powerful, and his word says do not Sin. If you sin, repent, and you won't get consequences.
Otherwise if people sin and do not repent, they will be dealt with by God.
Hope this helped!